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Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer.

2019 February 25

Explanation: What are those red filaments in the sky?It is a rarely seen form of lightning confirmed only about 30 years ago: red sprites.Recent research has shown that following a powerful positivecloud-to-ground lightning strike,red sprites may start as 100-meter balls ofionizedair that shoot down from about80-km high at 10 percent the speed of light and arequickly followedby a group of upward streaking ionized balls.The featured image, taken just over a week ago inKununurra, Western Australia,captured some red sprites while shooting a time-lapse sequence of a distant lightning storm.Pictured, green trees cover the foreground, dark mountains are seen on the horizon, ominous storm clouds hover over the distant land, while red sprites appear in front of stars far in the distance. Red sprites take only a fraction of a second to occur and are best seen whenpowerful thunderstorms are visible from the side.

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Astronomy Picture of the Day

astronomy | Definition & Facts | Britannica.com

Since the late 19th century astronomy has expanded to include astrophysics, the application of physical and chemical knowledge to an understanding of the nature of celestial objects and the physical processes that control their formation, evolution, and emission of radiation. In addition, the gases and dust particles around and between the stars have become the subjects of much research. Study of the nuclear reactions that provide the energy radiated by stars has shown how the diversity of atoms found in nature can be derived from a universe that, following the first few minutes of its existence, consisted only of hydrogen, helium, and a trace of lithium. Concerned with phenomena on the largest scale is cosmology, the study of the evolution of the universe. Astrophysics has transformed cosmology from a purely speculative activity to a modern science capable of predictions that can be tested.

Its great advances notwithstanding, astronomy is still subject to a major constraint: it is inherently an observational rather than an experimental science. Almost all measurements must be performed at great distances from the objects of interest, with no control over such quantities as their temperature, pressure, or chemical composition. There are a few exceptions to this limitationnamely, meteorites (most of which are from the asteroid belt, though some are from the Moon or Mars), rock and soil samples brought back from the Moon, samples of comet and asteroid dust returned by robotic spacecraft, and interplanetary dust particles collected in or above the stratosphere. These can be examined with laboratory techniques to provide information that cannot be obtained in any other way. In the future, space missions may return surface materials from Mars, or other objects, but much of astronomy appears otherwise confined to Earth-based observations augmented by observations from orbiting satellites and long-range space probes and supplemented by theory.

The solar system took shape 4.57 billion years ago, when it condensed within a large cloud of gas and dust. Gravitational attraction holds the planets in their elliptical orbits around the Sun. In addition to Earth, five major planets (Mercury, Venus, Mars, Jupiter, and Saturn) have been known from ancient times. Since then only two more have been discovered: Uranus by accident in 1781 and Neptune in 1846 after a deliberate search following a theoretical prediction based on observed irregularities in the orbit of Uranus. Pluto, discovered in 1930 after a search for a planet predicted to lie beyond Neptune, was considered a major planet until 2006, when it was redesignated a dwarf planet by the International Astronomical Union.

The average Earth-Sun distance, which originally defined the astronomical unit (AU), provides a convenient measure for distances within the solar system. The astronomical unit was originally defined by observations of the mean radius of Earths orbit but is now defined as 149,597,870.7 km (about 93 million miles). Mercury, at 0.4 AU, is the closest planet to the Sun, while Neptune, at 30.1 AU, is the farthest. Plutos orbit, with a mean radius of 39.5 AU, is sufficiently eccentric that at times it is closer to the Sun than is Neptune. The planes of the planetary orbits are all within a few degrees of the ecliptic, the plane that contains Earths orbit around the Sun. As viewed from far above Earths North Pole, all planets move in the same (counterclockwise) direction in their orbits.

Most of the mass of the solar system is concentrated in the Sun, with its 1.99 1033 grams. Together, all of the planets amount to 2.7 1030 grams (i.e., about one-thousandth of the Suns mass), and Jupiter alone accounts for 71 percent of this amount. The solar system also contains five known objects of intermediate size classified as dwarf planets and a very large number of much smaller objects collectively called small bodies. The small bodies, roughly in order of decreasing size, are the asteroids, or minor planets; comets, including Kuiper belt, Centaur, and Oort cloud objects; meteoroids; and interplanetary dust particles. Because of their starlike appearance when discovered, the largest of these bodies were termed asteroids, and that name is widely used, but, now that the rocky nature of these bodies is understood, their more descriptive name is minor planets.

The four inner, terrestrial planetsMercury, Venus, Earth, and Marsalong with the Moon have average densities in the range of 3.95.5 grams per cubic cm, setting them apart from the four outer, giant planetsJupiter, Saturn, Uranus, and Neptunewhose densities are all close to 1 gram per cubic cm, the density of water. The compositions of these two groups of planets must therefore be significantly different. This dissimilarity is thought to be attributable to conditions that prevailed during the early development of the solar system (see below Theories of origin). Planetary temperatures now range from around 170 C (330 F, 440 K) on Mercurys surface through the typical 15 C (60 F, 290 K) on Earth to 135 C (210 F, 140 K) on Jupiter near its cloud tops and down to 210 C (350 F, 60 K) near Neptunes cloud tops. These are average temperatures; large variations exist between dayside and nightside for planets closest to the Sun, except for Venus with its thick atmosphere.

The surfaces of the terrestrial planets and many satellites show extensive cratering, produced by high-speed impacts (see meteorite crater). On Earth, with its large quantities of water and an active atmosphere, many of these cosmic footprints have eroded, but remnants of very large craters can be seen in aerial and spacecraft photographs of the terrestrial surface. On Mercury, Mars, and the Moon, the absence of water and any significant atmosphere has left the craters unchanged for billions of years, apart from disturbances produced by infrequent later impacts. Volcanic activity has been an important force in the shaping of the surfaces of the Moon and the terrestrial planets. Seismic activity on the Moon has been monitored by means of seismometers left on its surface by Apollo astronauts and by Lunokhod robotic rovers. Cratering on the largest scale seems to have ceased about three billion years ago, although on the Moon there is clear evidence for a continued cosmic drizzle of small particles, with the larger objects churning (gardening) the lunar surface and the smallest producing microscopic impact pits in crystals in the lunar rocks.

All of the planets apart from the two closest to the Sun (Mercury and Venus) have natural satellites (moons) that are very diverse in appearance, size, and structure, as revealed in close-up observations from long-range space probes. The four outer dwarf planets have moons; Pluto has at least five moons, including one, Charon, fully half the size of Pluto itself. Over 200 asteroids and 80 Kuiper belt objects also have moons. Four planets (Jupiter, Saturn, Uranus, and Neptune), one dwarf planet (Haumea), and one Centaur object (Chariklo) have rings, disklike systems of small rocks and particles that orbit their parent bodies.

During the U.S. Apollo missions a total weight of 381.7 kg (841.5 pounds) of lunar material was collected; an additional 300 grams (0.66 pounds) was brought back by unmanned Soviet Luna vehicles. About 15 percent of the Apollo samples have been distributed for analysis, with the remainder stored at the NASA Johnson Space Center, Houston, Texas. The opportunity to employ a wide range of laboratory techniques on these lunar samples has revolutionized planetary science. The results of the analyses have enabled investigators to determine the composition and age of the lunar surface. Seismic observations have made it possible to probe the lunar interior. In addition, retroreflectors left on the Moons surface by Apollo astronauts have allowed high-power laser beams to be sent from Earth to the Moon and back, permitting scientists to monitor the Earth-Moon distance to an accuracy of a few centimetres. This experiment, which has provided data used in calculations of the dynamics of the Earth-Moon system, has shown that the separation of the two bodies is increasing by 4.4 cm (1.7 inches) each year. (For additional information on lunar studies, see Moon.)

Mercury is too hot to retain an atmosphere, but Venuss brilliant white appearance is the result of its being completely enveloped in thick clouds of carbon dioxide, impenetrable at visible wavelengths. Below the upper clouds, Venus has a hostile atmosphere containing clouds of sulfuric acid droplets. The cloud cover shields the planets surface from direct sunlight, but the energy that does filter through warms the surface, which then radiates at infrared wavelengths. The long-wavelength infrared radiation is trapped by the dense clouds such that an efficient greenhouse effect keeps the surface temperature near 465 C (870 F, 740 K). Radar, which can penetrate the thick Venusian clouds, has been used to map the planets surface. In contrast, the atmosphere of Mars is very thin and is composed mostly of carbon dioxide (95 percent), with very little water vapour; the planets surface pressure is only about 0.006 that of Earth. The outer planets have atmospheres composed largely of light gases, mainly hydrogen and helium.

Each planet rotates on its axis, and nearly all of them rotate in the same directioncounterclockwise as viewed from above the ecliptic. The two exceptions are Venus, which rotates in the clockwise direction beneath its cloud cover, and Uranus, which has its rotation axis very nearly in the plane of the ecliptic.

Some of the planets have magnetic fields. Earths field extends outward until it is disturbed by the solar windan outward flow of protons and electrons from the Sunwhich carries a magnetic field along with it. Through processes not yet fully understood, particles from the solar wind and galactic cosmic rays (high-speed particles from outside the solar system) populate two doughnut-shaped regions called the Van Allen radiation belts. The inner belt extends from about 1,000 to 5,000 km (600 to 3,000 miles) above Earths surface, and the outer from roughly 15,000 to 25,000 km (9,300 to 15,500 miles). In these belts, trapped particles spiral along paths that take them around Earth while bouncing back and forth between the Northern and Southern hemispheres, with their orbits controlled by Earths magnetic field. During periods of increased solar activity, these regions of trapped particles are disturbed, and some of the particles move down into Earths atmosphere, where they collide with atoms and molecules to produce auroras.

Jupiter has a magnetic field far stronger than Earths and many more trapped electrons, whose synchrotron radiation (electromagnetic radiation emitted by high-speed charged particles that are forced to move in curved paths, as under the influence of a magnetic field) is detectable from Earth. Bursts of increased radio emission are correlated with the position of Io, the innermost of the four Galilean moons of Jupiter. Saturn has a magnetic field that is much weaker than Jupiters, but it too has a region of trapped particles. Mercury has a weak magnetic field that is only about 1 percent as strong as Earths and shows no evidence of trapped particles. Uranus and Neptune have fields that are less than one-tenth the strength of Saturns and appear much more complex than that of Earth. No field has been detected around Venus or Mars.

More than 500,000 asteroids with well-established orbits are known, and thousands of additional objects are discovered each year. Hundreds of thousands more have been seen, but their orbits have not been as well determined. It is estimated that several million asteroids exist, but most are small, and their combined mass is estimated to be less than a thousandth that of Earth. Most of the asteroids have orbits close to the ecliptic and move in the asteroid belt, between 2.3 and 3.3 AU from the Sun. Because some asteroids travel in orbits that can bring them close to Earth, there is a possibility of a collision that could have devastating results (see Earth impact hazard).

Comets are considered to come from a vast reservoir, the Oort cloud, orbiting the Sun at distances of 20,00050,000 AU or more and containing trillions of icy objectslatent comet nucleiwith the potential to become active comets. Many comets have been observed over the centuries. Most make only a single pass through the inner solar system, but some are deflected by Jupiter or Saturn into orbits that allow them to return at predictable times. Halleys Comet is the best known of these periodic comets; its next return into the inner solar system is predicted for 2061. Many short-period comets are thought to come from the Kuiper belt, a region lying mainly between 30 AU and 50 AU from the Sunbeyond Neptunes orbit but including part of Plutosand housing perhaps hundreds of millions of comet nuclei. Very few comet masses have been well determined, but most are probably less than 1018 grams, one-billionth the mass of Earth.

Since the 1990s more than a thousand comet nuclei in the Kuiper belt have been observed with large telescopes; a few are about half the size of Pluto, and Pluto is the largest Kuiper belt object. Plutos orbital and physical characteristics had long caused it to be regarded as an anomaly among the planets. However, after the discovery of numerous other Pluto-like objects beyond Neptune, Pluto was seen to be no longer unique in its neighbourhood but rather a giant member of the local population. Consequently, in 2006 astronomers at the general assembly of the International Astronomical Union elected to create the new category of dwarf planets for objects with such qualifications. Pluto, Eris, and Ceres, the latter being the largest member of the asteroid belt, were given this distinction. Two other Kuiper belt objects, Makemake and Haumea, were also designated as dwarf planets.

Smaller than the observed asteroids and comets are the meteoroids, lumps of stony or metallic material believed to be mostly fragments of asteroids. Meteoroids vary from small rocks to boulders weighing a ton or more. A relative few have orbits that bring them into Earths atmosphere and down to the surface as meteorites. Most meteorites that have been collected on Earth are probably from asteroids. A few have been identified as being from the Moon, Mars, or the asteroid Vesta.

Meteorites are classified into three broad groups: stony (chondrites and achondrites; about 94 percent), iron (5 percent), and stony-iron (1 percent). Most meteoroids that enter the atmosphere heat up sufficiently to glow and appear as meteors, and the great majority of these vaporize completely or break up before they reach the surface. Many, perhaps most, meteors occur in showers (see meteor shower) and follow orbits that seem to be identical with those of certain comets, thus pointing to a cometary origin. For example, each May, when Earth crosses the orbit of Halleys Comet, the Eta Aquarid meteor shower occurs. Micrometeorites (interplanetary dust particles), the smallest meteoroidal particles, can be detected from Earth-orbiting satellites or collected by specially equipped aircraft flying in the stratosphere and returned for laboratory inspection. Since the late 1960s numerous meteorites have been found in the Antarctic on the surface of stranded ice flows (see Antarctic meteorites). Some meteorites contain microscopic crystals whose isotopic proportions are unique and appear to be dust grains that formed in the atmospheres of different stars.

The age of the solar system, taken to be close to 4.6 billion years, has been derived from measurements of radioactivity in meteorites, lunar samples, and Earths crust. Abundances of isotopes of uranium, thorium, and rubidium and their decay products, lead and strontium, are the measured quantities.

Assessment of the chemical composition of the solar system is based on data from Earth, the Moon, and meteorites as well as on the spectral analysis of light from the Sun and planets. In broad outline, the solar system abundances of the chemical elements decrease with increasing atomic weight. Hydrogen atoms are by far the most abundant, constituting 91 percent; helium is next, with 8.9 percent; and all other types of atoms together amount to only 0.1 percent.

The origin of Earth, the Moon, and the solar system as a whole is a problem that has not yet been settled in detail. The Sun probably formed by condensation of the central region of a large cloud of gas and dust, with the planets and other bodies of the solar system forming soon after, their composition strongly influenced by the temperature and pressure gradients in the evolving solar nebula. Less-volatile materials could condense into solids relatively close to the Sun to form the terrestrial planets. The abundant, volatile lighter elements could condense only at much greater distances to form the giant gas planets.

In the1990s astronomers confirmed that other stars have one or more planets revolving around them. Studies of these planetary systems have both supported and challenged astronomers theoretical models of how Earths solar system formed. Unlike the solar system, many extrasolar planetary systems have large gas giants like Jupiter orbiting very close to their stars, and in some cases these hot Jupiters are closer to their star than Mercury is to the Sun.

That so many gas giants, which form in the outer regions of their system, end up so close to their stars suggests that gas giants migrate and that such migration may have happened in the solar systems history. According to the Grand Tack hypothesis, Jupiter may have done so within a few million years of the solar systems formation. In this scenario, Jupiter is the first giant planet to form, at about 3 AU from the Sun. Drag from the protoplanetary disk causes it to fall inward to about 1.5 AU. However, by this time, Saturn begins to form at about 3 AU and captures Jupiter in a 3:2 resonance. (That is, for every three revolutions Jupiter makes, Saturn makes two.) The two planets migrate outward and clear away any material that would have gone to making Mars bigger. Mars should be bigger than Venus or Earth, but it is only half their size. The Grand Tack, in which Jupiter moves inward and then outward, explains Marss small size.

About 500 million years after the Grand Tack, according to the Nice Model (named after the French city where it was first proposed), after the four giant planetsJupiter, Saturn, Uranus, and Neptuneformed, they orbited 517 AU from the Sun. These planets were in a disk of smaller bodies called planetesimals and in orbital resonances with each other. About four billion years ago, gravitational interactions with the planetesimals increased the eccentricity of the planets orbits, driving them out of resonance. Saturn, Uranus and Neptune migrated outward, and Jupiter migrated slightly inward. (Uranus and Neptune may even have switched places.) This migration scattered the disk, causing the Late Heavy Bombardment. The final remnant of the disk became the Kuiper belt.

The origin of the planetary satellites is not entirely settled. As to the origin of the Moon, the opinion of astronomers long oscillated between theories that saw its origin and condensation as simultaneous with the formation of Earth and those that posited a separate origin for the Moon and its later capture by Earths gravitational field. Similarities and differences in abundances of the chemical elements and their isotopes on Earth and the Moon challenged each group of theories. Finally, in the 1980s a model emerged that gained the support of most lunar scientiststhat of a large impact on Earth and the expulsion of material that subsequently formed the Moon. (See Moon: Origin and evolution.) For the outer planets, with their multiple satellites, many very small and quite unlike one another, the picture is less clear. Some of these moons have relatively smooth icy surfaces, whereas others are heavily cratered; at least one, Jupiters Io, is volcanic. Some of the moons may have formed along with their parent planets, and others may have formed elsewhere and been captured.

The measurable quantities in stellar astrophysics include the externally observable features of the stars: distance, temperature, radiation spectrum and luminosity, composition (of the outer layers), diameter, mass, and variability in any of these. Theoretical astrophysicists use these observations to model the structure of stars and to devise theories for their formation and evolution. Positional information can be used for dynamical analysis, which yields estimates of stellar masses.

In a system dating back at least to the Greek astronomer-mathematician Hipparchus in the 2nd century bce, apparent stellar brightness (m) is measured in magnitudes. Magnitudes are now defined such that a first-magnitude star is 100 times brighter than a star of sixth magnitude. The human eye cannot see stars fainter than about sixth magnitude, but modern instruments used with large telescopes can record stars as faint as about 30th magnitude. By convention, the absolute magnitude (M) is defined as the magnitude that a star would appear to have if it were located at a standard distance of 10 parsecs. These quantities are related through the expression m M = 5 log10 r 5, in which r is the stars distance in parsecs.

The magnitude scale is anchored on a group of standard stars. An absolute measure of radiant power is luminosity, which is related to the absolute magnitude and usually expressed in ergs per second (ergs/sec). (Sometimes the luminosity is stated in terms of the solar luminosity, 3.86 1033 ergs/sec.) Luminosity can be calculated when m and r are known. Correction might be necessary for the interstellar absorption of starlight.

There are several methods for measuring a stars diameter. From the brightness and distance, the luminosity (L) can be calculated, and, from observations of the brightness at different wavelengths, the temperature (T) can be calculated. Because the radiation from many stars can be well approximated by a Planck blackbody spectrum (see Plancks radiation law), these measured quantities can be related through the expression L = 4R2T4, thus providing a means of calculating R, the stars radius. In this expression, is the Stefan-Boltzmann constant, 5.67 105 ergs/cm2K4sec, in which K is the temperature in kelvins. (The radius R refers to the stars photosphere, the region where the star becomes effectively opaque to outside observation.) Stellar angular diameters can be measured through interferometrythat is, the combining of several telescopes together to form a larger instrument that can resolve sizes smaller than those that an individual telescope can resolve. Alternatively, the intensity of the starlight can be monitored during occultation by the Moon, which produces diffraction fringes whose pattern depends on the angular diameter of the star. Stellar angular diameters of several milliarcseconds can be measured.

Many stars occur in binary systems (see binary star), in which the two partners orbit their mutual centre of mass. Such a system provides the best measurement of stellar masses. The period (P) of a binary system is related to the masses of the two stars (m1 and m2) and the orbital semimajor axis (mean radius; a) via Keplers third law: P2 = 42a3/G(m1 + m2). (G is the universal gravitational constant.) From diameters and masses, average values of the stellar density can be calculated and thence the central pressure. With the assumption of an equation of state, the central temperature can then be calculated. For example, in the Sun the central density is 158 grams per cubic cm; the pressure is calculated to be more than one billion times the pressure of Earths atmosphere at sea level and the temperature around 15 million K (27 million F). At this temperature, all atoms are ionized, and so the solar interior consists of a plasma, an ionized gas with hydrogen nuclei (i.e., protons), helium nuclei, and electrons as major constituents. A small fraction of the hydrogen nuclei possess sufficiently high speeds that, on colliding, their electrostatic repulsion is overcome, resulting in the formation, by means of a set of fusion reactions, of helium nuclei and a release of energy (see proton-proton cycle). Some of this energy is carried away by neutrinos, but most of it is carried by photons to the surface of the Sun to maintain its luminosity.

Other stars, both more and less massive than the Sun, have broadly similar structures, but the size, central pressure and temperature, and fusion rate are functions of the stars mass and composition. The stars and their internal fusion (and resulting luminosity) are held stable against collapse through a delicate balance between the inward pressure produced by gravitational attraction and the outward pressure supplied by the photons produced in the fusion reactions.

Stars that are in this condition of hydrostatic equilibrium are termed main-sequence stars, and they occupy a well-defined band on the Hertzsprung-Russell (H-R) diagram, in which luminosity is plotted against colour index or temperature. Spectral classification, based initially on the colour index, includes the major spectral types O, B, A, F, G, K and M, each subdivided into 10 parts (see star: Stellar spectra). Temperature is deduced from broadband spectral measurements in several standard wavelength intervals. Measurement of apparent magnitudes in two spectral regions, the B and V bands (centred on 4350 and 5550 angstroms, respectively), permits calculation of the colour index, CI = mB mV, from which the temperature can be calculated.

For a given temperature, there are stars that are much more luminous than main-sequence stars. Given the dependence of luminosity on the square of the radius and the fourth power of the temperature (R2T4 of the luminosity expression above), greater luminosity implies larger radius, and such stars are termed giant stars or supergiant stars. Conversely, stars with luminosities much less than those of main-sequence stars of the same temperature must be smaller and are termed white dwarf stars. Surface temperatures of white dwarfs typically range from 10,000 to 12,000 K (18,000 to 21,000 F), and they appear visually as white or blue-white.

The strength of spectral lines of the more abundant elements in a stars atmosphere allows additional subdivisions within a class. Thus, the Sun, a main-sequence star, is classified as G2 V, in which the V denotes main sequence. Betelgeuse, a red giant with a surface temperature about half that of the Sun but with a luminosity of about 10,000 solar units, is classified as M2 Iab. In this classification, the spectral type is M2, and the Iab indicates a giant, well above the main sequence on the H-R diagram.

The range of physically allowable masses for stars is very narrow. If the stars mass is too small, the central temperature will be too low to sustain fusion reactions. The theoretical minimum stellar mass is about 0.08 solar mass. An upper theoretical bound called the Eddington limit, of several hundred solar masses, has been suggested, but this value is not firmly defined. Stars as massive as this will have luminosities about one million times greater than that of the Sun.

A general model of star formation and evolution has been developed, and the major features seem to be established. A large cloud of gas and dust can contract under its own gravitational attraction if its temperature is sufficiently low. As gravitational energy is released, the contracting central material heats up until a point is reached at which the outward radiation pressure balances the inward gravitational pressure, and contraction ceases. Fusion reactions take over as the stars primary source of energy, and the star is then on the main sequence. The time to pass through these formative stages and onto the main sequence is less than 100 million years for a star with as much mass as the Sun. It takes longer for less massive stars and a much shorter time for those much more massive.

Once a star has reached its main-sequence stage, it evolves relatively slowly, fusing hydrogen nuclei in its core to form helium nuclei. Continued fusion not only releases the energy that is radiated but also results in nucleosynthesis, the production of heavier nuclei.

Stellar evolution has of necessity been followed through computer modeling, because the timescales for most stages are generally too extended for measurable changes to be observed, even over a period of many years. One exception is the supernova, the violently explosive finale of certain stars. Different types of supernovas can be distinguished by their spectral lines and by changes in luminosity during and after the outburst. In Type Ia, a white dwarf star attracts matter from a nearby companion; when the white dwarfs mass exceeds about 1.4 solar masses, the star implodes and is completely destroyed. Type II supernovas are not as luminous as Type Ia and are the final evolutionary stage of stars more massive than about eight solar masses. Type Ib and Ic supernovas are like Type II in that they are from the collapse of a massive star, but they do not retain their hydrogen envelope.

The nature of the final products of stellar evolution depends on stellar mass. Some stars pass through an unstable stage in which their dimensions, temperature, and luminosity change cyclically over periods of hours or days. These so-called Cepheid variables serve as standard candles for distance measurements (see above Determining astronomical distances). Some stars blow off their outer layers to produce planetary nebulas. The expanding material can be seen glowing in a thin shell as it disperses into the interstellar medium while the remnant core, initially with a surface temperature as high as 100,000 K (180,000 F), cools to become a white dwarf. The maximum stellar mass that can exist as a white dwarf is about 1.4 solar masses and is known as the Chandrasekhar limit. More-massive stars may end up as either neutron stars or black holes.

The average density of a white dwarf is calculated to exceed one million grams per cubic cm. Further compression is limited by a quantum condition called degeneracy (see degenerate gas), in which only certain energies are allowed for the electrons in the stars interior. Under sufficiently great pressure, the electrons are forced to combine with protons to form neutrons. The resulting neutron star will have a density in the range of 10141015 grams per cubic cm, comparable to the density within atomic nuclei. The behaviour of large masses having nuclear densities is not yet sufficiently understood to be able to set a limit on the maximum size of a neutron star, but it is thought to be less than three solar masses.

Still more-massive remnants of stellar evolution would have smaller dimensions and would be even denser that neutron stars. Such remnants are conceived to be black holes, objects so compact that no radiation can escape from within a characteristic distance called the Schwarzschild radius. This critical dimension is defined by Rs = 2GM/c2. (Rs is the Schwarzschild radius, G is the gravitational constant, M is the objects mass, and c is the speed of light.) For an object of three solar masses, the Schwarzschild radius would be about three kilometres. Radiation emitted from beyond the Schwarzschild radius can still escape and be detected.

Although no light can be detected coming from within a black hole, the presence of a black hole may be manifested through the effects of its gravitational field, as, for example, in a binary star system. If a black hole is paired with a normal visible star, it may pull matter from its companion toward itself. This matter is accelerated as it approaches the black hole and becomes so intensely heated that it radiates large amounts of X-rays from the periphery of the black hole before reaching the Schwarzschild radius. Some candidates for stellar black holes have been founde.g., the X-ray source Cygnus X-1. Each of them has an estimated mass clearly exceeding that allowable for a neutron star, a factor crucial in the identification of possible black holes. (Supermassive black holes that do not originate as individual stars are thought to exist at the centre of active galaxies; see below Study of other galaxies and related phenomena.)

Whereas the existence of stellar black holes has been strongly indicated, the existence of neutron stars was confirmed in 1968 when they were identified with the then newly discovered pulsars, objects characterized by the emission of radiation at short and extremely regular intervals, generally between 1 and 1,000 pulses per second and stable to better than a part per billion. Pulsars are considered to be rotating neutron stars, remnants of some supernovas.

Stars are not distributed randomly throughout space. Many stars are in systems consisting of two or three members separated by less than 1,000 AU. On a larger scale, star clusters may contain many thousands of stars. Galaxies are much larger systems of stars and usually include clouds of gas and dust.

The solar system is located within the Milky Way Galaxy, close to its equatorial plane and about 8 kiloparsecs from the galactic centre. The galactic diameter is about 30 kiloparsecs, as indicated by luminous matter. There is evidence, however, for nonluminous matterso-called dark matterextending out nearly twice this distance. The entire system is rotating such that, at the position of the Sun, the orbital speed is about 220 km per second (almost 500,000 miles per hour) and a complete circuit takes roughly 240 million years. Application of Keplers third law leads to an estimate for the galactic mass of about 100 billion solar masses. The rotational velocity can be measured from the Doppler shifts observed in the 21-cm emission line of neutral hydrogen and the lines of millimetre wavelengths from various molecules, especially carbon monoxide. At great distances from the galactic centre, the rotational velocity does not drop off as expected but rather increases slightly. This behaviour appears to require a much larger galactic mass than can be accounted for by the known (luminous) matter. Additional evidence for the presence of dark matter comes from a variety of other observations. The nature and extent of the dark matter (or missing mass) constitutes one of todays major astronomical puzzles.

There are about 100 billion stars in the Milky Way Galaxy. Star concentrations within the galaxy fall into three types: open clusters, globular clusters, and associations (see star cluster). Open clusters lie primarily in the disk of the galaxy; most contain between 50 and 1,000 stars within a region no more than 10 parsecs in diameter. Stellar associations tend to have somewhat fewer stars; moreover, the constituent stars are not as closely grouped as those in the clusters and are for the most part hotter. Globular clusters, which are widely scattered around the galaxy, may extend up to about 100 parsecs in diameter and may have as many as a million stars. The importance to astronomers of globular clusters lies in their use as indicators of the age of the galaxy. Because massive stars evolve more rapidly than do smaller stars, the age of a cluster can be estimated from its H-R diagram. In a young cluster the main sequence will be well populated, but in an old cluster the heavier stars will have evolved away from the main sequence. The extent of the depopulation of the main sequence provides an index of age. In this way, the oldest globular clusters have been found to be about 12.5 billion years old, which should therefore be the minimum age for the galaxy.

The interstellar medium, composed primarily of gas and dust, occupies the regions between the stars. On average, it contains less than one atom in each cubic centimetre, with about 1 percent of its mass in the form of minute dust grains. The gas, mostly hydrogen, has been mapped by means of its 21-cm emission line. The gas also contains numerous molecules. Some of these have been detected by the visible-wavelength absorption lines that they impose on the spectra of more-distant stars, while others have been identified by their own emission lines at millimetre wavelengths. Many of the interstellar molecules are found in giant molecular clouds, wherein complex organic molecules have been discovered.

In the vicinity of a very hot O- or B-type star, the intensity of ultraviolet radiation is sufficiently high to ionize the surrounding hydrogen out to a distance as great as 100 parsecs to produce an H II region, known as a Strmgren sphere. Such regions are strong and characteristic emitters of radiation at radio wavelengths, and their dimensions are well calibrated in terms of the luminosity of the central star. Using radio interferometers, astronomers are able to measure the angular diameters of H II regions even in some external galaxies and can thereby deduce the great distances to those remote systems. This method can be used for distances up to about 30 megaparsecs. (For additional information on H II regions, see nebula: Diffuse nebulae (H II regions).)

Interstellar dust grains scatter and absorb starlight, the effect being roughly inversely proportional to wavelength from the infrared to the near ultraviolet. As a result, stellar spectra tend to be reddened. Absorption typically amounts to about one magnitude per kiloparsec but varies considerably in different directions. Some dusty regions contain silicate materials, identified by a broad absorption feature around a wavelength of 10 m. Other prominent spectral features in the infrared range have been sometimes, but not conclusively, attributed to graphite grains and polycyclic aromatic hydrocarbons (PAHs).

Starlight often shows a small degree of polarization (a few percent), with the effect increasing with stellar distance. This is attributed to the scattering of the starlight from dust grains that have been partially aligned in a weak interstellar magnetic field. The strength of this field is estimated to be a few microgauss, very close to the strength inferred from observations of nonthermal cosmic radio noise. This radio background has been identified as synchrotron radiation, emitted by cosmic-ray electrons traveling at nearly the speed of light and moving along curved paths in the interstellar magnetic field. The spectrum of the cosmic radio noise is close to what is calculated on the basis of measurements of the cosmic rays near Earth.

Cosmic rays constitute another component of the interstellar medium. Cosmic rays that are detected in the vicinity of Earth comprise high-speed nuclei and electrons. Individual particle energies, expressed in electron volts (eV; 1 eV = 1.6 1012 erg), range with decreasing numbers from about 106 eV to more than 1020 eV. Among the nuclei, hydrogen nuclei are the most plentiful at 86 percent, helium nuclei next at 13 percent, and all other nuclei together at about 1 percent. Electrons are about 2 percent as abundant as the nuclear component. (The relative numbers of different nuclei vary somewhat with kinetic energy, while the electron proportion is strongly energy-dependent.)

A minority of cosmic rays detected in Earths vicinity are produced in the Sun, especially at times of increased solar activity (as indicated by sunspots and solar flares). The origin of galactic cosmic rays has not yet been conclusively identified, but they are thought to be produced in stellar processes such as supernova explosions, perhaps with additional acceleration occurring in the interstellar regions. (For additional information on interstellar matter, see Milky Way Galaxy: The general interstellar medium.)

The central region of the Milky Way Galaxy is so heavily obscured by dust that direct observation has become possible only with the development of astronomy at nonvisual wavelengthsnamely, radio, infrared, and, more recently, X-ray and gamma-ray wavelengths. Together, these observations have revealed a nuclear region of intense activity, with a large number of separate sources of emission and a great deal of dust. Detection of gamma-ray emission at a line energy of 511,000 eV, which corresponds to the annihilation of electrons and positrons (the antimatter counterpart of electrons), along with radio mapping of a region no more than 20 AU across, points to a very compact and energetic source, designated Sagittarius A*, at the centre of the galaxy. Sagittarius A* is a supermassive black hole with a mass equivalent to 4,310,000 Suns.

Galaxies are normally classified into three principal types according to their appearance: spiral, elliptical, and irregular. Galactic diameters are typically in the tens of kiloparsecs and the distances between galaxies typically in megaparsecs.

Spiral galaxiesof which the Milky Way system is a characteristic exampletend to be flattened, roughly circular systems with their constituent stars strongly concentrated along spiral arms. These arms are thought to be produced by traveling density waves, which compress and expand the galactic material. Between the spiral arms exists a diffuse interstellar medium of gas and dust, mostly at very low temperatures (below 100 K [280 F, 170 C]). Spiral galaxies are typically a few kiloparsecs in thickness; they have a central bulge and taper gradually toward the outer edges.

Ellipticals show none of the spiral features but are more densely packed stellar systems. They range in shape from nearly spherical to very flattened and contain little interstellar matter. Irregular galaxies number only a few percent of all stellar systems and exhibit none of the regular features associated with spirals or ellipticals.

Properties vary considerably among the different types of galaxies. Spirals typically have masses in the range of a billion to a trillion solar masses, with ellipticals having values from 10 times smaller to 10 times larger and the irregulars generally 10100 times smaller. Visual galactic luminosities show similar spreads among the three types, but the irregulars tend to be less luminous. In contrast, at radio wavelengths the maximum luminosity for spirals is usually 100,000 times less than for ellipticals or irregulars.

Quasars are objects whose spectra display very large redshifts, thus implying (in accordance with the Hubble law) that they lie at the greatest distances (see above Determining astronomical distances). They were discovered in 1963 but remained enigmatic for many years. They appear as starlike (i.e., very compact) sources of radio waveshence their initial designation as quasi-stellar radio sources, a term later shortened to quasars. They are now considered to be the exceedingly luminous cores of distant galaxies. These energetic cores, which emit copious quantities of X-rays and gamma rays, are termed active galactic nuclei (AGN) and include the object Cygnus A and the nuclei of a class of galaxies called Seyfert galaxies. They may be powered by the infall of matter into supermassive black holes.

The Milky Way Galaxy is one of the Local Group of galaxies, which contains about four dozen members and extends over a volume about two megaparsecs in diameter. Two of the closest members are the Magellanic Clouds, irregular galaxies about 50 kiloparsecs away. At about 740 kiloparsecs, the Andromeda Galaxy is one of the most distant in the Local Group. Some members of the group are moving toward the Milky Way system while others are traveling away from it. At greater distances, all galaxies are moving away from the Milky Way Galaxy. Their speeds (as determined from the redshifted wavelengths in their spectra) are generally proportional to their distances. The Hubble law relates these two quantities (see above Determining astronomical distances). In the absence of any other method, the Hubble law continues to be used for distance determinations to the farthest objectsthat is, galaxies and quasars for which redshifts can be measured.

Cosmology is the scientific study of the universe as a unified whole, from its earliest moments through its evolution to its ultimate fate. The currently accepted cosmological model is the big bang. In this picture, the expansion of the universe started in an intense explosion 13.8 billion years ago. In this primordial fireball, the temperature exceeded one trillion K, and most of the energy was in the form of radiation. As the expansion proceeded (accompanied by cooling), the role of the radiation diminished, and other physical processes dominated in turn. Thus, after about three minutes, the temperature had dropped to the one-billion-K range, making it possible for nuclear reactions of protons to take place and produce nuclei of deuterium and helium. (At the higher temperatures that prevailed earlier, these nuclei would have been promptly disrupted by high-energy photons.) With further expansion, the time between nuclear collisions had increased and the proportion of deuterium and helium nuclei had stabilized. After a few hundred thousand years, the temperature must have dropped sufficiently for electrons to remain attached to nuclei to constitute atoms. Galaxies are thought to have begun forming after a few million years, but this stage is very poorly understood. Star formation probably started much later, after at least a billion years, and the process continues today.

Observational support for this general model comes from several independent directions. The expansion has been documented by the redshifts observed in the spectra of galaxies. Furthermore, the radiation left over from the original fireball would have cooled with the expansion. Confirmation of this relic energy came in 1965 with one of the most striking cosmic discoveries of the 20th centurythe observation, at short radio wavelengths, of a widespread cosmic radiation corresponding to a temperature of almost 3 K (about 270 C [454 F]). The shape of the observed spectrum is an excellent fit with the theoretical Planck blackbody spectrum. (The present best value for this temperature is 2.735 K, but it is still called three-degree radiation or the cosmic microwave background.) The spectrum of this cosmic radio noise peaks at approximately a one-millimetre wavelength, which is in the far infrared, a difficult region to observe from Earth; however, the spectrum has been well mapped by the Cosmic Background Explorer (COBE), Wilkinson Microwave Anisotropy Probe, and Planck satellites. Additional support for the big bang theory comes from the observed cosmic abundances of deuterium and helium. Normal stellar nucleosynthesis cannot produce their measured quantities, which fit well with calculations of production during the early stages of the big bang.

Early surveys of the cosmic background radiation indicated that it is extremely uniform in all directions (isotropic). Calculations have shown that it is difficult to achieve this degree of isotropy unless there was a very early and rapid inflationary period before the expansion settled into its present mode. Nevertheless, the isotropy posed problems for models of galaxy formation. Galaxies originate from turbulent conditions that produce local fluctuations of density, toward which more matter would then be gravitationally attracted. Such density variations were difficult to reconcile with the isotropy required by observations of the 3 K radiation. This problem was solved when the COBE satellite was able to detect the minute fluctuations in the cosmic background from which the galaxies formed.

The very earliest stages of the big bang are less well understood. The conditions of temperature and pressure that prevailed prior to the first microsecond require the introduction of theoretical ideas of subatomic particle physics. Subatomic particles are usually studied in laboratories with giant accelerators, but the region of particle energies of potential significance to the question at hand lies beyond the range of accelerators currently available. Fortunately, some important conclusions can be drawn from the observed cosmic helium abundance, which is dependent on conditions in the early big bang. The observed helium abundance sets a limit on the number of families of certain types of subatomic particles that can exist.

The age of the universe can be calculated in several ways. Assuming the validity of the big bang model, one attempts to answer the question: How long has the universe been expanding in order to have reached its present size? The numbers relevant to calculating an answer are Hubbles constant (i.e., the current expansion rate), the density of matter in the universe, and the cosmological constant, which allows for change in the expansion rate. In 2003 a calculation based on a fresh determination of Hubbles constant yielded an age of 13.7 billion 200 million years, although the precise value depends on certain assumed details of the model used. Independent estimates of stellar ages have yielded values less than this, as would be expected, but other estimates, based on supernova distance measurements, have arrived at values of about 15 billion years, still consistent, within the errors. In the big bang model the age is proportional to the reciprocal of Hubbles constant, hence the importance of determining H as reliably as possible. For example, a value for H of 100 km/sec/Mpc would lead to an age less than that of many stars, a physically unacceptable result.

A small minority of astronomers have developed alternative cosmological theories that are seriously pursued. The overwhelming professional opinion, however, continues to support the big bang model.

Finally, there is the question of the future behaviour of the universe: Is it open? That is to say, will the expansion continue indefinitely? Or is it closed, such that the expansion will slow down and eventually reverse, resulting in contraction? (The final collapse of such a contracting universe is sometimes termed the big crunch.) The density of the universe seems to be at the critical density; that is, the universe is neither open nor closed but flat. So-called dark energy, a kind of repulsive force that is now believed to be a major component of the universe, appears to be the decisive factor in predictions of the long-term fate of the cosmos. If this energy is a cosmological constant (as proposed in 1917 by Albert Einstein to correct certain problems in his model of the universe), then the result would be a big chill. In this scenario, the universe would continue to expand, but its density would decrease. While old stars would burn out, new stars would no longer form. The universe would become cold and dark. The dark (nonluminous) matter component of the universe, whose composition remains unknown, is not considered sufficient to close the universe and cause it to collapse; it now appears to contribute only a fourth of the density needed for closure.

An additional factor in deciding the fate of the universe might be the mass of neutrinos. For decades the neutrino had been postulated to have zero mass, although there was no compelling theoretical reason for this to be so. From the observation of neutrinos generated in the Sun and other celestial sources such as supernovas, in cosmic-ray interactions with Earths atmosphere, and in particle accelerators, investigators have concluded that neutrinos have some mass, though only an extremely small fraction of the mass of an electron. Although there are vast numbers of neutrinos in the universe, the sum of such small neutrino masses appears insufficient to close the universe.

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astronomy | Definition & Facts | Britannica.com

Astronomy | Definition of Astronomy by Merriam-Webster

: the study of objects and matter outside the earth’s atmosphere and of their physical and chemical properties

Some may find it easy to confuse astronomy and astrology. At one time, these two words actually were synonymous (that is, astronomy once meant what astrology means today), but they have since moved apart from each other. In current use, astronomy is concerned with the study of objects and matter outside the earth’s atmosphere, while astrology is the purported divination of how stars and planets influence our lives. Put bluntly, astronomy is a science, and astrology is not.

Recent Examples on the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word ‘astronomy.’ Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

12th century, in the meaning defined above

Middle English astronomie, from Anglo-French, from Latin astronomia, from Greek, from astr- + -nomia -nomy

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19 Feb 2019

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: a science concerned with objects and matter outside the earth’s atmosphere and of their motions and makeup

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About – The New Jim Crow

The New Jim Crow is a stunning account of the rebirth of a caste-like system in the United States, one that has resulted in millions of African Americans locked behind bars and then relegated to a permanent second-class statusdenied the very rights supposedly won in the Civil Rights Movement. Since its publication in 2010, the book has appeared on theNew York Timesbestseller list for more than a year; been dubbed the secular bible of a new social movement by numerous commentators, including Cornel West;and has led to consciousness-raising efforts in universities, churches, community centers, re-entry centers, and prisons nationwide. The New Jim Crow tells a truth our nation has been reluctant to face.

As the United States celebrates its triumph over race with the election of Barack Obama, the majority of black men in major urban areas are under correctional control or saddled with criminal records for life. Jim Crow laws were wiped off the books decades ago, but today an extraordinary percentage of the African American community is warehoused in prisons or trapped in a parallel social universe, denied basic civil and human rightsincluding the right to vote; the right to serve on juries; and the right to be free of legal discrimination in employment, housing, access to education and public benefits. Today, it is no longer socially permissible to use race explicitly as a justification for discrimination, exclusion, and social contempt. Yet as civil-rights-lawyer-turned-legal-scholar Michelle Alexander demonstrates, it is perfectly legal to discriminate against convicted criminals in nearly all the ways in which it was once legal to discriminate against African Americans. Once labeled a felon, even for a minor drug crime, the old forms of discrimination are suddenly legal again. In her words, we have not ended racial caste in America; we have merely redesigned it.

Alexander shows that, by targeting black men through the War on Drugs and decimating communities of color, the U.S. criminal justice system functions as a contemporary system of racial control, even as it formally adheres to the principle of colorblindness.

The New Jim Crowchallenges the civil rights communityand all of usto place mass incarceration at the forefront of a new movement for racial justice in America.

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About – The New Jim Crow

A Brief History of the Drug War | Drug Policy Alliance

This video from hip hop legend Jay Z and acclaimed artist Molly Crabapple depicts the drug wars devastating impact on the Black community from decades of biased law enforcement.

The video traces the drug war from President Nixon to the draconian Rockefeller Drug Laws to the emerging aboveground marijuana market that is poised to make legal millions for wealthy investors doing the same thing that generations of people of color have been arrested and locked up for. After you watch the video, read on to learn more about the discriminatory history of the war on drugs.

Many currently illegal drugs, such as marijuana, opium, coca, and psychedelics have been used for thousands of years for both medical and spiritual purposes. So why are some drugs legal and other drugs illegal today? It’s not based on any scientific assessment of the relative risks of these drugs but it has everything to do with who is associated with these drugs.

The first anti-opium laws in the 1870s were directed at Chinese immigrants. The first anti-cocaine laws in the early 1900s were directed at black men in the South. The first anti-marijuana laws, in the Midwest and the Southwest in the 1910s and 20s, were directed at Mexican migrants and Mexican Americans. Today, Latino and especially black communities are still subject to wildly disproportionate drug enforcement and sentencing practices.

In the 1960s, as drugs became symbols of youthful rebellion, social upheaval, and political dissent, the government halted scientific research to evaluate their medical safety and efficacy.

In June 1971, President Nixon declared a war on drugs. He dramatically increased the size and presence of federal drug control agencies, and pushed through measures such as mandatory sentencing and no-knock warrants.

A top Nixon aide, John Ehrlichman, later admitted: You want to know what this was really all about. The Nixon campaign in 1968, and the Nixon White House after that, had two enemies: the antiwar left and black people. You understand what Im saying. We knew we couldnt make it illegal to be either against the war or black, but by getting the public to associate the hippies with marijuana and blacks with heroin, and then criminalizing both heavily, we could disrupt those communities. We could arrest their leaders, raid their homes, break up their meetings, and vilify them night after night on the evening news. Did we know we were lying about the drugs? Of course we did.Nixon temporarily placed marijuana in Schedule One, the most restrictive category of drugs, pending review by a commission he appointed led by Republican Pennsylvania Governor Raymond Shafer.

In 1972, the commission unanimously recommended decriminalizing the possession and distribution of marijuana for personal use. Nixon ignored the report and rejected its recommendations.

Between 1973 and 1977, however, eleven states decriminalized marijuana possession. In January 1977, President Jimmy Carter was inaugurated on a campaign platform that included marijuana decriminalization. In October 1977, the Senate Judiciary Committee voted to decriminalize possession of up to an ounce of marijuana for personal use.

Within just a few years, though, the tide had shifted. Proposals to decriminalize marijuana were abandoned as parents became increasingly concerned about high rates of teen marijuana use. Marijuana was ultimately caught up in a broader cultural backlash against the perceived permissiveness of the 1970s.

The presidency of Ronald Reagan marked the start of a long period of skyrocketing rates of incarceration, largely thanks to his unprecedented expansion of the drug war. The number of people behind bars for nonviolent drug law offenses increased from 50,000 in 1980 to over 400,000 by 1997.

Public concern about illicit drug use built throughout the 1980s, largely due to media portrayals of people addicted to the smokeable form of cocaine dubbed crack. Soon after Ronald Reagan took office in 1981, his wife, Nancy Reagan, began a highly-publicized anti-drug campaign, coining the slogan “Just Say No.”

This set the stage for the zero tolerance policies implemented in the mid-to-late 1980s. Los Angeles Police Chief Daryl Gates, who believed that casual drug users should be taken out and shot, founded the DARE drug education program, which was quickly adopted nationwide despite the lack of evidence of its effectiveness. The increasingly harsh drug policies also blocked the expansion of syringe access programs and other harm reduction policies to reduce the rapid spread of HIV/AIDS.

In the late 1980s, a political hysteria about drugs led to the passage of draconian penalties in Congress and state legislatures that rapidly increased the prison population. In 1985, the proportion of Americans polled who saw drug abuse as the nation’s “number one problem” was just 2-6 percent. The figure grew through the remainder of the 1980s until, in September 1989, it reached a remarkable 64 percent one of the most intense fixations by the American public on any issue in polling history. Within less than a year, however, the figure plummeted to less than 10 percent, as the media lost interest. The draconian policies enacted during the hysteria remained, however, and continued to result in escalating levels of arrests and incarceration.

Although Bill Clinton advocated for treatment instead of incarceration during his 1992 presidential campaign, after his first few months in the White House he reverted to the drug war strategies of his Republican predecessors by continuing to escalate the drug war. Notoriously, Clinton rejected a U.S. Sentencing Commission recommendation to eliminate the disparity between crack and powder cocaine sentences.

He also rejected, with the encouragement of drug czar General Barry McCaffrey, Health Secretary Donna Shalalas advice to end the federal ban on funding for syringe access programs. Yet, a month before leaving office, Clinton asserted in a Rolling Stone interview that “we really need a re-examination of our entire policy on imprisonment” of people who use drugs, and said that marijuana use “should be decriminalized.”

At the height of the drug war hysteria in the late 1980s and early 1990s, a movement emerged seeking a new approach to drug policy. In 1987, Arnold Trebach and Kevin Zeese founded the Drug Policy Foundation describing it as the loyal opposition to the war on drugs. Prominent conservatives such as William Buckley and Milton Friedman had long advocated for ending drug prohibition, as had civil libertarians such as longtime ACLU Executive Director Ira Glasser. In the late 1980s they were joined by Baltimore Mayor Kurt Schmoke, Federal Judge Robert Sweet, Princeton professor Ethan Nadelmann, and other activists, scholars and policymakers.

In 1994, Nadelmann founded The Lindesmith Center as the first U.S. project of George Soros Open Society Institute. In 2000, the growing Center merged with the Drug Policy Foundation to create the Drug Policy Alliance.

George W. Bush arrived in the White House as the drug war was running out of steam yet he allocated more money than ever to it. His drug czar, John Walters, zealously focused on marijuana and launched a major campaign to promote student drug testing. While rates of illicit drug use remained constant, overdose fatalities rose rapidly.

The era of George W. Bush also witnessed the rapid escalation of the militarization of domestic drug law enforcement. By the end of Bush’s term, there were about 40,000 paramilitary-style SWAT raids on Americans every year mostly for nonviolent drug law offenses, often misdemeanors. While federal reform mostly stalled under Bush, state-level reforms finally began to slow the growth of the drug war.

Politicians now routinely admit to having used marijuana, and even cocaine, when they were younger. When Michael Bloomberg was questioned during his 2001 mayoral campaign about whether he had ever used marijuana, he said, “You bet I did and I enjoyed it.” Barack Obama also candidly discussed his prior cocaine and marijuana use: “When I was a kid, I inhaled frequently that was the point.”

Public opinion has shifted dramatically in favor of sensible reforms that expand health-based approaches while reducing the role of criminalization in drug policy.

Marijuana reform has gained unprecedented momentum throughout the Americas. Alaska, California, Colorado, Nevada, Oregon, Maine, Massachusetts, Washington State, and Washington D.C. have legalized marijuana for adults. In December 2013, Uruguay became the first country in the world to legally regulate marijuana. In Canada, Prime Minister Justin Trudeau plans legalize marijuana for adults by 2018.

In response to a worsening overdose epidemic, dozens of U.S. states passed laws to increase access to the overdose antidote, naloxone, as well as 911 Good Samaritan laws to encourage people to seek medical help in the event of an overdose.

Yet the assault on American citizens and others continues, with 700,000 people still arrested for marijuana offenses each year and almost 500,000 people still behind bars for nothing more than a drug law violation.

President Obama, despite supporting several successful policy changes such as reducing the crack/powder sentencing disparity, ending the ban on federal funding for syringe access programs, and ending federal interference with state medical marijuana laws did not shift the majority of drug policy funding to a health-based approach.

Now, the new administration is threatening to take us backward toward a 1980s style drug war. President Trump is calling for a wall to keep drugs out of the country, and Attorney General Jeff Sessions has made it clear that he does not support the sovereignty of states to legalize marijuana, and believes good people dont smoke marijuana.

Progress is inevitably slow, and even with an administration hostile to reform there is still unprecedented momentum behind drug policy reform in states and localities across the country. The Drug Policy Alliance and its allies will continue to advocate for health-based reforms such as marijuana legalization, drug decriminalization, safe consumption sites, naloxone access, bail reform, and more.

We look forward to a future where drug policies are shaped by science and compassion rather than political hysteria.

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A Brief History of the Drug War | Drug Policy Alliance

Political crime – Wikipedia

In criminology, a political crime or political offence is an offence involving overt acts or omissions (where there is a duty to act), which prejudice the interests of the state, its government, or the political system. It is to be distinguished from state crime, in which it is the states that break both their own criminal laws or public international law.[1]

States will define as political crimes any behaviour perceived as a threat, real or imagined, to the state’s survival, including both violent and non-violent oppositional crimes. A consequence of such criminalisation may be that a range of human rights, civil rights, and freedoms are curtailed, and conduct which would not normally be considered criminal per se (in other words, that is not antisocial according to those who engage in it) is criminalised at the convenience of the group holding power.

Thus, there may be a question of the morality of a law which simply criminalises ordinary political dissent,[2] even though the majority of those who support the current regime may consider criminalisation of politically motivated behaviour an acceptable response when the offender is driven by more extreme political, ideological, religious or other beliefs,

At one extreme, crimes such as treason, sedition, and terrorism are political because they represent a direct challenge to the government in power. Espionage is usually considered a criminal act.[3] But offenders do not have to aim to overthrow the government or to depose its leaders to be acting in a way perceived as “political”. A state may perceive it threatening if individuals advocate change to the established order, or argue the need for reform of long-established policies, or engage in acts signifying some degree of disloyalty, e.g. by burning the nation’s flag in public. But the scope of such crimes can be rather less direct.

Structural functionist criminologists recognise that states invest their resources in maintaining order through social conformity, i.e. a particular culture is encouraged and maintained through the primary social discourses which may include religious, economic, social, or other less formal concerns. Any interference with the media of communication or the sets of meanings embedded in the communications themselves may be perceived as a threat to the political authority of the state. Hence, whether in hard copy or electronically, if individuals distribute material containing uncensored information which undermines the credibility of state-controlled news media, this may be considered threatening.

Moreover, even an offence against non-governmental institutions, persons, or practices may be deemed political. Violence or even discrimination against an ethnic or racial group, as well trade union strikes or picketing against private employers, can be perceived as a political crime when those in power see such conduct as undermining the political (and economic) stability of the state. In this context, note that the Law Enforcement Code of Conduct passed by the International Association of Chiefs of Police says in part: “The fundamental duties of a police officer include serving the community, safeguarding lives and property, protecting the innocent, keeping the peace and ensuring the rights of all to liberty, equality and justice” (cited in Robinson, 2002). This code requires that police behave in a courteous and fair manner, that they treat all citizens in a respectable and decent manner, and that they never use unnecessary force. When they do, it is argued that this constitutes a crime (e.g. as an assault) and, if it is institutionalised, then over time, the use of unnecessary force become a state crime.

Marxist criminologists argue that most political crime arises from the efforts of the state to reproduce the structures of inequality: racism, sexism, ethnic preference as well as class advantages. Thus, states will protect property rights and reduce the rights of trade unions to represent the interests of the poor. Even war could be grounded in the problems of local capitalists in wealthy countries in the effort to move raw materials, profits and jobs in a globalised political economy, and opposing such a war will be a political crime. Marxists do not dispute that, for a society to function efficiently, social order is necessary. But they consider that, in all societies, one class, usually characterised as the “ruling class”, gains far more than other classes. Marxists agree with functionalists that socialisation plays a crucial role in promoting conformity and order. However, unlike the latter, they are highly critical of the ideas, values and norms of “capitalist ideology”. Modern Marxists point to education and the media as socialising agencies, which delude or “mystify” the working class into conforming to a social order, which works against its real interests. Thus, all controls which directly or indirectly explit the criminal law to control access to the discourses are political crimes.

Miller says that one of the defining characteristics of power in modern history has been the rationalisation and bureaucratisation of law. Legal codification, or at least debates over the merits of legal codification, became an almost global phenomenon in the nineteenth century as state power was centralised. In particular, the rationalisation of criminal law standardised not just the concept of crime, but was adopted as the means to eliminate the “deviant” as a threat to a modern, uniform, moral standard. In this, the religious establishment began to play a new role in defining “evil” in which threats to the political or social norm became as dangerous as threats to religious orthodoxy. Thus, political speech became one of the most likely activities to be criminalised. The freedom of association and to meet may also be criminalised if the purpose is to express oppositional political views.

Because a political offender may be fighting against a tyrannical government, treaties have usually specified that a person cannot be extradited for a political offense. Thomas Jefferson wrote:[4]

People convicted or suspected of certain crimes classified as terrorism by the government of their country (or some foreign countries) reject that classification. They consider that their fight is a legitimate one using legitimate means, and thus their crimes should be more appropriately called political crimes and justify special treatment in the penal system (as if they were soldiers in a war and therefore covered by the Geneva Convention). States tend to consider the political nature of the crimes an aggravating factor in the sentencing process and make no distinction between the terrorists and “ordinary” offenders, e.g. the convicted murderers of Action Directe consider themselves political prisoners.

Where there is no clear separation between the state and the prevailing religion, the edicts of the church may be codified as law and enforced by the secular policing and judicial authorities. This is a highly functionalist mechanism for enforcing conformity in all aspects of cultural life and the use of the label “crime” adds an extra layer of stigma to those convicted.

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Political crime – Wikipedia

Environmental Crimes – UNICRI

Environmental crimes

UNICRI considers environmental crime, including its links with other forms of crime, a serious and growing danger for development, global stability and international security.

Since 1991, UNICRI has contributed to combating crimes against the environment and related emerging threats through applied research, awareness and capacity-building initiatives. UNICRI has built a strong international network of experts and practitioners from major international organization, law enforcement agencies, NGOs and academic entities active in the field.

Environmental crimes encompass a broad list of illicit activities, including illegal trade in wildlife; smuggling of ozone-depleting substances (ODS); illicit trade of hazardous waste; illegal, unregulated, and unreported fishing; and illegal logging and trade in timber. On one side, environmental crimes are increasingly affecting the quality of air, water and soil, threatening the survival of species and causing uncontrollable disasters. On the other, environmental crimes also impose a security and safety threat to a large number of people and have a significant negative impact on development and the rule of law. Despite these issues, environmental crimes often fail to prompt the appropriate governmental response. Often perceived as victimless and incidental crimes, environmental crimes frequently rank low on the law enforcement priority list, and are commonly punished with administrative sanctions, themselves often unclear and low.

The involvement of organized criminal groups acting across borders is one of many factors that have favoured the considerable expansion of environmental crimes in recent years. Led by vast financial gains and facilitated by a low risk of detection and scarce conviction rates, criminal networks and organized criminal groups are becoming increasingly interested in such illicit transnational activities. These phenomena fuel corruption and money-laundering, and undermine the rule of law, ultimately affecting the public twice: first, by putting at risk citizens health and safety; and second, by diverting resources that would otherwise be allocated to services other than criminal activities.

The level of organization needed for these crimes indicates a link with other serious offences, including theft, fraud, corruption, drugs and human trafficking, counterfeiting, firearms smuggling, and money laundering, several of which have been substantiated by investigations. Therefore, environmental crimes represent today an emerging form of transnational organized crime requiring more in-depth analysis and better-coordinated responses at national, regional and international levels.

The first research projects conducted by UNICRI addressed the issue of environmental law, and in particular explored the limits and potentials of applying criminal law in crimes related to environment. In June 1998, UNICRI organised in Rome a seminar on international environmental conventions and the administration of criminal law. Since then, the Institute has focused on the involvement of organized criminal groups in environmental crime.

To increase awareness of the threat of environmental crime, UNICRI contributed to the organization of the conference entitled Illicit trafficking in waste: a global emergency (Rome, December 2011), with the participation of the Ministry of the Environment of Italy, parliamentarians, international partners such as the International Criminal Police Organization (INTERPOL), and many stakeholders involved in countering trafficking in and dumping of toxic waste. To enhance understanding of the dynamics of environmental crime, the Institute implemented a research and data collection project focused on the dumping of illegal waste and hazardous materials, including e-waste, and the involvement of organized crime.

In partnership with several research institutes, civil society organizations, and municipalities, UNICRI has launched a process for consultation at the international level on the involvement of organized crime in environmental crime, with a view to identify a set of recommendations for more effective policies and actions at the national, regional and international levels. To that end, the Institute, in partnership with the United Nations Environment Programme (UNEP), has organized an international conference in Italy on 29 and 30 October 2012 (see dedicated section).

UNICRI has implemented several international and regional applied-research projects related to the illegal trade and trafficking goods having an adverse impact on the environment, including e-waste, illicit pesticides and precious metals (see dedicated sections).

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Environmental Crimes – UNICRI

Trump Signs Directive: Space Force Will Be Run By Air Force

President Donald Trump signed Space Policy Directive 4 (SPD-4) today, organizing all military space functions under a new Space Force.

Space Force 2.0

U.S. President Donald Trump signed a directive today that organizes all military space functions under a new Space Force. The Space Force will be run entirely under the current U.S. Air Force — at least for the time being.

That means a future Space Force would function more like the Marine Corps, which is part of the Navy, than an entirely separate branch of the military — which is what the Trump administration first suggested back in June.

A More Popular Approach

The news comes after Trump signed an executive order in December, calling for the creation of a “U.S. Space Command” to streamline and consolidate space operations.

The plans still have to receive Congress approval before its creation, but organizing it under the Air Force could be a way to warm lawmakers up to the idea, as Defense News suggests.

Agreeable Idea

The Washington Post points out that the Directive could also be a more agreeable idea to the Pentagon as it would create far less bureaucracy.

Today’s news doesn’t necessarily rule out future plans for a standalone Space Force military branch. But it could save military officials a headache in the near future.

READ MORE: Trump approves plan to create Space Force, but puts it under Air Force control, as Pentagon officials had wanted [The Washington Post]

More on Space Force: The US May Soon Have The World’s First Space Force

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Trump Signs Directive: Space Force Will Be Run By Air Force

Users of Crypto Site Where Dead CEO Lost $196M Are Preparing Suit

QuadrigaCX has about two weeks left to its stay to raise the money it owes before anyone can sue, but a judge just appointed law firms to its customers.

Making Moves

Remember that cryptocurrency exchange that said it lost $196 million of its customers’ money when CEO Gerald Cotten died — prompting conspiracy theories Cotten faked his own death?

Well, those 115,000 customers just lawyered up.

Ticking Clock

Michael Wood, a justice on Nova Scotia’s Supreme Court, issued a ruling Tuesday that QuadrigaCX customers would be represented by two law firms, Miller Thomson as well as Cox & Palmer, in the event of a class-action lawsuit, according to CoinDesk.

So far, no one has filed suit against QuadrigaCX — though the users’ new lawyers can start preparing one, according to CoinDesk. On Feb. 5, the courts approved a 30-day stay at the company’s request. That leaves QuadrigaCX with about two more weeks to settle the matter and come up with $196 million on its own before anyone can sue.

Next Steps

Once the stay expires on March 7, the crypto exchange may try to have it extended. But that appeal would come before Judge Wood.

Given his move to prepare QuadrigaCX customers for a potential lawsuit, Wood may decide that QuadrigaCX was given enough time and open up the floor to any lawsuits.

READ MORE: Judge Appoints Law Firms to Represent QuadrigaCX Customers [CoinDesk]

More on QuadrigaCX: Indian Hospital Fires Back at Rumors That Crypto CEO Faked Death

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Users of Crypto Site Where Dead CEO Lost $196M Are Preparing Suit

Lab-Grown Meat Could Be Worse for the Environment

The benefits of lab-grown meat will depend on scientists' ability to produce it sustainably, and right now, we don't know if that's even possible.

Growing Change

Meat farming is a major contributor of the greenhouse gases driving climate change. To ensure we never have to choose between a livable planet and a juicy hamburger, scientists are attempting to efficiently grow convincing imitation meat in the lab using everything from volcano-dwelling microbes to stem cells.

But new research suggests the efforts of those scientists might be in vain — it turns out that growing meat in the lab might actually do more damage to the environment than producing it the traditional way.

Meat Market

For their study, published Tuesday in the journal Frontiers in Sustainable Food Systems, researchers from the Oxford Martin School compared the potential impact on the global temperature over the next 1,000 years of three cattle farming methods and four potential methods for growing meat in the lab.

Their comparison revealed that yes, lab-grown meat could be better for the environment — but it won’t be better by default.

“The climate impacts of cultured meat production will depend on what level of sustainable energy generation can be achieved, as well as the efficiency of future culture processes,” researcher John Lynch told the BBC. “If the lab-grown meat is quite energy intensive to produce then they could end up being worse for the climate than cows are.”

Apples and Oranges

The methane emitted by cattle also has a different kind of impact on the environment than the carbon dioxide that scientists might pump into the atmosphere while producing meat in the lab.

“Per tonne emitted, methane has a much larger warming impact than carbon dioxide,” researcher Raymond Pierrehumbert said in a press release. “However, it only remains in the atmosphere for about 12 years whereas carbon dioxide persists and accumulates for millennia.”

Ultimately, this research reveals that it’s still too soon to know whether lab-grown meat could actually solve our agriculture-caused climate woes — which means we might still be headed toward a future in which we need to trade at least some of our steaks for salads.

READ MORE: Cultured Lab Meat May Make Climate Change Worse [BBC]

More on lab-grown meat: To Feed a Hungry Planet, We’re All Going to Need to Eat Less Meat

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Lab-Grown Meat Could Be Worse for the Environment

Japan Sends Robot Into the Nuclear Hell of the Fukushima Reactor

A robot just physically examined the radioactive fuel at the damaged Fukushima Nuclear Reactor. It's the first step toward an ongoing cleanup mission.

Nuclear Probe

The Tokyo Electric Power Company (TEPCO) just sent a robot into one of the reactors of the Fukushima nuclear power plant, which was destroyed by a tsunami back in 2011.

The robot made contact with the melted fuel, picking it up and putting it back down to determine whether it was solid enough to cart away during a future mission, according to Ars Technica.

Image Credit: TEPCO

The Claw

Fukushima won’t be fully decommissioned for another 30 to 40 years. But this robotic mission is the first step toward determining how other robots will go about cleaning it up.

In this case, the robot was able to pick up small chunks of the radioactive fuel at five of the six test sites, all of which were located inside one of the power plant’s three damaged reactors. TEPCO published a video of the process taken by the robot’s built-in camera, in which you can see a robotic claw position itself around and pick up small pieces of fuel.

Catch and Release

None of the radioactive fuel left the reactor along with the robot when the mission was over. But that wasn’t the plan. Rather, this mission marks the first time that a robot has been able to physically examine Fukushima’s fuel.

The team hopes to start retrieving some of the deadly fuel in 2021, now that they know it can be physically lifted.

READ MORE: Japanese utility makes first contact with melted Fukushima fuel [Ars Technica]

More on Fukushima: A $320 Million Ice Wall Still Can’t Contain Radioactive Water Near Fukushima

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Japan Sends Robot Into the Nuclear Hell of the Fukushima Reactor

WHO Says UN Should Reclassify Marijuana as Less Dangerous

New Class

Marijuana could soon be reclassified on an international scale.

In 1948, the United Nations (UN) established the World Health Organization (WHO) to serve as its conduit to all things health-related. Now, the agency is recommending that the UN reclassify marijuana to a less restrictive narcotics schedule — a move that could have a huge impact on public health worldwide.

Narcotics Treaty

Under the UN’s Single Convention on Narcotic Drugs, an international treaty that regulates the production and sale of certain drugs, cannabis is listed as a Schedule IV drug. Thats the most restrictive class, reserved for drugs that have “particularly dangerous properties.”

Earlier this month, the WHO published new recommendations to the UN regarding the classification of marijuana in the medical journal The BMJAccording to the WHO, there’s growing evidence that cannabis has medical applications, and the UN should reschedule the plant to take into account these applications.

Medical Marijuana

The WHO’s proposal to reclassify marijuana could go before the UN’s Commission on Narcotic Drugs as soon as March, at which point 53 countries will have the option of voting on it.

Although a vote to reclassify wouldn’t make cannabis legal everywhere overnight, it would mark a major shift in how political leaders view the drug — which could have a huge impact on the drug’s use for medical purposes.

Scientists have already noted potential uses for cannabis to treat everything from psychosis and epilepsy to heart disease and Alzheimer’s, but researching these links hasn’t been easy given marijuana’s legal status.

If governments decide to revisit their cannabis laws in the wake of a UN reclassification, it might be easier for researchers to gain approval — and funding — for their marijuana-focused studies, meaning we could see a dramatic increase in the number of cannabis-based medical treatments in the future.

READ MORE: In Historic Announcement, the World Health Organization (WHO) Proposes Removing Cannabis From Most Dangerous Drug Category [Good News Network]

More on marijuana: New Senate Bill Would Legalize Marijuana Nationwide

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WHO Says UN Should Reclassify Marijuana as Less Dangerous

Australian License Plates Can Now Include Emoji

As of March 1, drivers in Queensland, Australia will be able to include one of five emoji in their license plates — a startling break from tradition.

License to Emoji

It’s the natural evolution of the vanity license plate: emoji.

As of March 1, drivers in Queensland, Australia will be able to include one of five emoji in their license plates: laughing out loud, winking face, sunglasses, heart eyes, and the classic smiley face.

“For quite some time we’ve seen that you can support your favourite team or your favourite town with a symbol on your number plate,” Royal Automobile Club of Queensland spokeswoman Rebecca Michael told 7News Brisbane. “And using an emoji is no different.”

Cool Sunglasses Face

If you drive a vehicle in Queensland, you can pre-order your own customized plate right now on the website of government-approved plate vendor Personalised Plates Queensland (PPQ.)

Drivers will like need to pay a fee somewhere between $160 to $500 in Australian dollars to get the new emoji, according to 7News.

Mo’ ‘Mojis, Mo’ Problems

One problem remains: police could be thrown off by the unusual new plates.

“How do you write down the emoji in your number plate after an accident?” Queensland Law Society president Bill Potts asked the Brisbane Times.

READ MORE: Queensland drivers set to get emoji number plates [new.com.au]

More on license plates: A “Smart” License Plate: To Buy or Not to Buy?

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Australian License Plates Can Now Include Emoji

New Gadget Detects Lifeforms From Long Distances

A new tool called the TreePol spectropolarimeter could someday scan for extraterrestrial life without picking up any false positives.

Upgrading SETI

A new scientific instrument with the extraordinary name “TreePol spectropolarimeter” can be used to detect the presence of lifeforms from several kilometers away.

And while right now the device is best used for spotting faraway plants, a high-powered version of the tool could someday serve as the most reliable means of searching for extraterrestrial life to date, according to a press release published Tuesday by The Netherlands Organization for Scientific Research (NWO).

Advanced Search

Often, when scientists talk about which exoplanets or moons might harbor life, they weigh factors like water, atmospheric oxygen, and the presence of organic molecules. But that opens the door to all kinds of false positives — there’s an underwater lake on Mars, for instance, but that doesn’t mean anything lives there.

But TreePol detects light that’s been rotated after bouncing off molecules found only in living things. The tool was specifically built to detect foliage, but can also detect light that bounced off of most living things on Earth, according to the press release.

Long Shot

It’s possible that the molecules that make up whatever extraterrestrial life might exist out there doesn’t interact with light in the same way as life on Earth. But the important distinction here is that nothing else on Earth does — nothing will trigger TreePol’s sensors except for living things.

Right now, the team is preparing to test whether TreePol could be used to analyze crops from a plane or satellite, slowly ramping up the distance over which TreePol scans. If those tests work, the scientists will investigate whether they can use it to scan the cosmos, perhaps by sending TreePol up to the International Space Station.

READ MORE: Reliable method for detecting extraterrestrial life is used on Earth for the first time [NWO Newsroom]

More on extraterrestrial life: Scientists Need to Solve These Two Mysteries to Find Life on Mars

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New Gadget Detects Lifeforms From Long Distances

Scientists Found a “River of Stars” Flowing Through the Milky Way

New research has uncovered a stellar stream comprising 4,000 stars flowing through the Milky Way remarkably close to the Earth.

Flow On

The Milky Way is home to a variety of star clusters. Most of the time, its gravity quickly pulls these clusters apart, but some clusters have enough mass to remain stuck together, and sometimes the clusters form stellar streams, which are river-like stretches of stars that orbit the galaxy.

Now, researchers have identified a billion-year-old stellar stream comprising nearly 4,000 stars — and it’s remarkably close to our Sun.

Close Encounter

In a study published in the journal Astronomy and Astrophysics on Thursday, a team from the University of Vienna details its discovery of this new stellar stream, which is approximately 1,300 light-years long and 160 light-years wide.

The team discovered the stream using data from the European Space Agency’s Gaia satellite, and according to researcher João Alves, it’s been hiding in plain sight.

“Astronomers have been looking at, and through, this new stream for a long time, as it covers most of the night sky, but only now realize it is there,” he explained in a press release.

“As soon as we investigated this particular group of stars in more detail, we knew that we had found what we were looking for: A coeval, stream-like structure, stretching for hundreds of parsecs across a third of the entire sky,” researcher Verena Fürnkranz said. “It was so thrilling to be part of a new discovery.”

Down River

The researchers are already looking ahead to what new insights they may be able to glean from this river of stars, positing that it could lead to new information on how galaxies gain their stars, the discovery of new exoplanets, and an improved understanding of the Milky Way’s mass and gravitational field.

“Finding things close to home is very useful,” Alves said. “It means they are not too faint nor too blurred for further detailed exploration, as astronomers dream.”

READ MORE: Astronomers Have Detected a Previously Unnoticed ‘River of Stars’ Flowing Past Earth [Science Alert]

More on stellar streams: Dark Energy Survey Discovers Remnants of Other Galaxies Within Our Own

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Scientists Found a “River of Stars” Flowing Through the Milky Way

Bangladesh Declares “War on Pornography,” Blocks TikTok

The Bangladeshi government is scrubbing the internet of porn. But it's also monitoring people's personal social media accounts for provocative images.

Porn Ban

Over the past week, Bangladesh has blocked tens of thousands of sites and apps and is policing the social media accounts of celebrities in an effort to scrub the nation’s internet of pornography.

The porn purge comes as part of the government’s push to crack down on adult-oriented content like porn and gambling, which originated with a November decision in Bangladesh’s High Court, according to Al Jazeera.

Declaring War

“I want to create a safe and secure internet for all Bangladeshis, including children,” said Mustafa Jabbar, Bangladeshi posts and telecommunications minister. “And this is my war against pornography. And this will be a continuous war.”

That war on porn also seems to involve micromanaging the lives of celebrities. The Bangladeshi government recently ordered a local actress to delete what it determined were provocative pictures from her various social media accounts, Al Jazeera reports.

“We are monitoring the local Facebook profiles, YouTube channels and websites, also,” Jabbar said. “A few of them were taken down for having obscene content. We advised a few others not to post anything that goes against our social norms.”

Behind Seven Proxies

So far, internet service providers have complied with the government’s demands. But the nation’s porn hungry internet users can still access porn with a little technological wizardry.

A Bangladeshi official confirmed that the country’s new regulations can be skirted using a virtual private network or mirror websites, according to Al Jazeera.

READ MORE: Bangladesh blocks 20,000 websites in anti-porn ‘war’ [Al Jazeera]

More on censorship: Google Is Censoring Search Results to Hide Russian Corruption

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Bangladesh Declares “War on Pornography,” Blocks TikTok

Elon Musk: Bitcoin Is “Brilliant” And “Paper Money Is Going Away”

Tesla CEO Elon Musk shared his thoughts on Bitcoin and other cryptocurrencies during a podcast interview with ARK Invest.

“Seriously?”

Elon Musk is talking cryptocurrency. The real Elon Musk, not one of those Twitter scammers.

On Tuesday, Tesla’s CEO sat down for a podcast interview with ARK Invest, a tech investment firm. In addition to chatting about electric vehicles and self-driving cars, the interviewers decided to throw Musk an “off-topic” question about cryptocurrencies.

After an initially incredulous response — “Crypto, seriously?” — Musk went on to elaborate on his thoughts about crypto and Bitcoin in particular — and while he sees the value in both, don’t expect Tesla to get involved in the space any time soon.

Pros and Cons

During the interview, Musk admitted that he thinks “the Bitcoin structure is quite brilliant” and that there might be “some merit to Ethereum as well and maybe some others.”

He went on to discuss the uses of the cryptocurrency with ARK Invest founder Cathie Wood, who noted that “there were $1.3 trillion worth of transactions in bitcoin, and we don’t see it here because it’s not for pizza or Coke.”

“It might be for coke,” Musk deadpanned, in an apparent drug joke, prompting laughs from his interviewers.

“We figure it’s business-to-business in Africa where it is prohibitively expensive to convert from one nation’s currency to another,” Wood continued. “It really is very important. It’s money over IP for them. It’s free transmission of money, and that’s really important to opening up the world.”

“It bypasses currency controls,” Musk said. “Paper money is going away, and crypto is a far better way to transfer value than pieces of paper, that’s for sure. That has its pros and cons.”

Tesla Coin

As for whether Tesla would ever get involved in crypto, Musk doesn’t see that happening any time soon.

His company’s primary goal is to “accelerate the advent of sustainable energy,” according to Musk, and as he noted during the interview, mining cryptocurrencies is computationally energy intensive.

“I’m not sure it would be a good use for Tesla resources to get involved in crypto,” he concluded.

“Just to clarify,” ARK Invest analyst Tasha Keeney asked later, “Tesla’s not going to start selling bitcoin anytime soon?”

“No, we’re not,” Musk replied.

READ MORE: Elon Musk Calls Bitcoin ‘Brilliant,’ Better Than Paper Money for Value Transfer [CoinDesk]

More on crypto: Fake Elon Musks Clutter Twitter With Crypto Scams

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Elon Musk: Bitcoin Is “Brilliant” And “Paper Money Is Going Away”

Vampire Clinic That Sold Young Blood to the Wealthy Closes Shop

Bad Blood

Ambrosia Health, the controversial clinic that sold transfusions of young, healthy people’s blood, has “ceased patient treatments,” according to the company’s website.

The decision to stop taking patients comes after an official statement from FDA commissioner Scott Gottlieb this week, which described the company’s practices as a dangerous scam.

Dr. Acula

Ambrosia claimed its transfusions of a younger person’s blood could reverse health problems and extend a person’s life — a controversial and unproven notion.

The company never published the results of its self-funded clinical experiments, and recent evidence suggests that these transfusions could have been dangerous from the start.

Vampire Empire

It’s unclear whether Ambrosia plans to resume operations in the future or if the FDA’s warning rang the company’s death toll. Futurism reached out to the company with questions, and this article will be updated if we hear back.

Either way, the wealthy will need to get their controversial medical treatments somewhere else for the time being.

READ MORE: ‘Young blood’ company Ambrosia halts patient treatments after FDA warning [NBC]

More on Ambrosia Health: The FDA Warns: Transfusions of Young Blood Are a Dangerous Scam

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Vampire Clinic That Sold Young Blood to the Wealthy Closes Shop

Elon Musk: Teslas Will Be Fully Self-Driving By Next Year

Full Autonomy

According to Elon Musk, Tesla’s cars are nearly ready for fully autonomous driving.

“I think we will be feature complete — full self-driving — this year,” Musk told Cathie Wood and Tasha Keeney of ARK Invest in a podcast on Tuesday. “Meaning the car will be able to find you in a parking lot, pick you up and take you all the way to your destination without an intervention, this year.”

Car Naps

By next year, you’ll be able to take a nap behind the wheel, Musk claimed in the same interview.

“My guess as to when we would think it is safe for somebody to essentially fall asleep and wake up at their destination? Probably towards the end of next year,” he said.

And he’s willing to stand by his words: “I would say I am of certain of that,” he said. “That is not a question mark.”

Big Promises

Musk is no stranger to making big promises. As it stands right now, Tesla’s Autopilot can make lane changes, and navigate highway ramps — but it still can’t handle most other roads.

In October, Tesla dropped the “full self-driving” mode from the Model 3, with Musk claiming it was “causing too much confusion” in a tweet.

The race to have cars take over all driving functions is on. Alphabet’s Waymo launched a robo-taxi service in Arizona in December.

But even Waymo’s cars require human safety drivers to take control on multiple occasions throughout a single ride.

READ MORE: Elon Musk Promises a Really Truly Self-Driving Tesla in 2020 [Wired]

More on Tesla: Teslas Are Getting a “Party and Camping Mode”

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