The Universe is assumed to be around 13.8 billion years old, but new calculations suggest it could be younger than that.

This artists impression shows the evolution of the Universe beginning with the Big Bang on the left followed by the appearance of the Cosmic Microwave Background. The formation of the first stars ends the cosmic dark ages, followed by the formation of galaxies. Image credit: M. Weiss / Harvard-Smithsonian Center for Astrophysics.

Approaches to date the Big Bang, which gave birth to the Universe, rely on mathematics and computational modeling, using distance estimates of the oldest stars, the behavior of galaxies and the rate of the Universes expansion.

The idea is to compute how long it would take all objects to return to the beginning.

A key calculation for dating is the Hubbles constant, named after Edwin Hubble who first calculated the Universes expansion rate in 1929.

Another recent technique uses observations of the Cosmic Microwave Background (CMB), the oldest light in the Universe.

These methods reach different conclusions, said University of Oregons Professor James Schombert, lead author of the study.

Professor Schombert and his colleagues unveil a new approach that recalibrates a distance-measuring tool known as the baryonic Tully-Fisher relation independently of Hubbles constant.

The distance scale problem, as it is known, is incredibly difficult because the distances to galaxies are vast and the signposts for their distances are faint and hard to calibrate, Professor Schombert said.

The astronomers recalculated the Tully-Fisher approach, using accurately defined distances in a linear computation of the 50 galaxies as guides for measuring the distances of 95 other galaxies.

The Universe is ruled by a series of mathematical patterns expressed in equations, Professor Schombert said.

The new approach more accurately accounts for the mass and rotational curves of galaxies to turn those equations into numbers like age and expansion rate.

The approach determines the Hubbles constant at 75.1 kilometers per second per megaparsec (km/s/Mpc), give or take 2.3.

All Hubbles constant values lower than 70 km/s/Mpc can be ruled out with 95% degree of confidence, the researchers said.

Traditionally used measuring techniques over the past 50 years have set the value at 75 km/s/Mpc, but CMB computes a rate of 67 km/s/Mpc.

The CMB technique, while using different assumptions and computer simulations, should still arrive at the same estimate.

Calculations drawn from observations of NASAs Wilkinson Microwave Anisotropy Probe (WAMP) in 2013 put the age of the Universe at 13.77 billion years, which, for the moment, represents the standard model of Big Bang cosmology.

The differing Hubbles constant values from the various techniques generally estimate the Universes age at between 11.4 billion and 14.5 billion years.

The new study, based in part on observations made with NASAs Spitzer Space Telescope, adds a new element to how calculations to reach Hubbles constant can be set, by introducing a purely empirical method, using direct observations, to determine the distance to galaxies.

Our resulting value is on the high side of the different schools of cosmology, signaling that our understanding of the physics of the Universe is incomplete with the hope of new physics in the future, Professor Schombert said.

The results were published in the Astronomical Journal.

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James Schombert et al. 2020. Using the Baryonic Tully-Fisher Relation to Measure Ho. AJ 160, 71; doi: 10.3847/1538-3881/ab9d88

This article is based on text provided by the University of Oregon.

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Study: Universe Might Be 1.2 Billion Years Younger | Astronomy - Sci-News.com

After the COVID-19 rules about social distancing went into effect, I developed a morning routine of jogging through the woods near my home. During the first months, I focused on the green branches that stretch upward towards the sky, but recently I started to notice the debris of tree trunks lying on the ground. There are many such remnants, eaten by termites, rotting and ultimately dispersing into the underlying soil. A glimpse at the forest reveals a sequence of evolutionary phases in the history of trees that lived or died at different times.

The phenomenon happens in other contexts. For example, I recently completed a nine-year term as chair of the Astronomy Department at Harvard. And only now have I begun to notice the former chairs scattered around me, just like those tree trunks in the woods.

Entering a new stage of life can be humbling. We acquire a false sense of permanence from reviewing the frozen past, as if it were a statue that will never erode. But this view is shortsighted, since each moment can also be seen a new beginning, shaped by forces beyond our control and swirling on a grander scale.

Old-fashioned astronomy was also permeated by a false sense of permanence. Astronomers collected still images of the universe, creating the impression that nothing really changes under the sunor above it, either. But just like the revelation from my stroll through the woods, these snapshots showed stars and galaxies of different ages, at various evolutionary phases along their history. Computer simulations helped us patch together the full story by solving the equations of motion for matter, starting from the initial conditions imprinted on the cosmic microwave background at early cosmic times. By generating snapshots of an artificial cosmos similar to those captured by telescopes, these simulations unraveled our cosmic roots. The scientific insight that emerged is that the likely origins for our existence were quantum fluctuations in the early universe. Perhaps we should add Quantum Mechanics Day to our annual celebrations of Mothers Day and Fathers Day.

There are some missing pages in the photo album made up of our observations, however: the period known as the cosmic dawn, for example, when the first stars and galaxies turned on. These missing pages will be filled in the coming decade by the next generation of telescopes, such as the James Webb Space Telescope (JWST), the ground-based "extremely large" telescopes and the Hydrogen Epoch of Reionization Array (HERA).

To reveal a more literal gap in the sky, the Event Horizon Telescope recently captured a still image of the silhouette of the black hole in the giant galaxy M87. The next goal is to obtain a sequence of images or a video, showing the time variability of the accretion flow around the black hole.

The tradition of still images makes sense when dealing with systems like galaxies, which evolve on a timescale of billions of years. But the universe also exhibits transient fireworks that flare up and dim during a human lifetime. Observing them is the motivation behind the Legacy Survey of Space and Time (LSST) on the Vera C. Rubin Observatory, which will have its first light soon. LSST will be a filming project, documenting nearly a thousand deep multicolor images per patch of the southern sky over a decade and recording the most extensive video of the universe ever taken with its plethora of transients in full glory.

Some of the LSST flares are expected to be the counterparts of gravitational wave sources detected by LIGO/Virgo or LISA. Their discovery will usher in multi-messenger astronomy based on both gravitational and electromagnetic waves emitted by the same sources, providing new insights about the central engines that power these transients. The related standard sirens could serve as new rulers for measuring precise distances in cosmology.

Within the Milky Way, transient events close to Earth could lead to catastrophe. A supernova explosion, for example, could cause a mass extinction on an unprecedented scale. If a meteor similar to the one that hit the unpopulated regions near Chelyabinsk in 2013 or Tunguska in 1908 hit New York City, it could cause a far larger death toll and economic damage than COVID-19. Or consider the impact of a blob of hot gas from the Sun, a so-called coronal mass ejection of the type that missed the Earth in 2012. Such an event could shut off communication systems, disable satellites and damage power grids. Altogether, astronomical alerts about such celestial threats could be crucial for securing the longevity of our species.

Of greatest relevance for our long-term survival is identifying large objects on a collision course with the Earth, similar to the Chicxulub asteroid that killed the dinosaurs 66 million years ago. In 2005, Congress passed a bill requiring NASA to find and track at least 90 percent of all near-Earth objects larger than 140 meters (enough to cause regional devastation) by 2020. Only a third of these objects have been identified in the sky so far. In a recent paper with my undergraduate student Amir Siraj, we explained some puzzling properties of the Chicxulub asteroid as a tidal breakup of a long-period comet that passed close to the sun. If future sky surveys alert us to another fragment whose apparent size grows rapidly against the sky, wed better have a contingency plan to deflect its trajectoryor else immediately call our realtor.

Keeping up with the challenge of precision cosmology for the next few decades can demonstrate that the Hubble constant, which describes the expansion rate of the universe, is not really a constant, in accordance with the expected Sandage-Loeb test. In the long run, the only thing that stays constant is change. The accelerated expansion of the universe under the influence of so-called dark energy will be the ultimate manifestation of extragalactic social distancing in the post-COVID-19 era, preventing any future contact between us and civilizations outside our galaxy.

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A Movie of the Evolving Universe, Potentially Scary - Scientific American

As of July 4, the NASA Exoplanet Archive (https://exoplanetarchive.ipac.caltech.edu/) listed 4,183 confirmed exoplanets, planets orbiting other stars, with another 2,089 candidate planets awaiting confirmation. NASA and other institutions have only studied a tiny percent of all the stars in our Milky Way. Based on the sample so far, astronomers estimate that planets outnumber stars in our galaxy. That means the Milky Way contains several hundred billion planets.

These exoplanets come in a bewildering variety. Some are Jupiter-size planets so close to their parent star that the heat from the star evaporates them. Some Earth-size planets get so hot, they rain liquid metal from their clouds. Most confirmed planets are significantly larger than Earth, but thats because larger planets are easier to discover than smaller planets. Astronomers estimate that Earth-size planets number in the billions.

Being the size of Earth doesnt mean such a planet has life on it. Many factors play into planet habitability. Distance to its parent star determines surface temperature. Too hot or too cold and habitability becomes unlikely. The type of parent star plays a crucial role. Stars smaller than our sun often produce large, dangerous stellar flares.

If Earth is a good example of what conditions necessary for a planet to support life, water is an absolute must. On our planet, where theres water, life exists, even at the bottom of the ocean, with near-freezing temperatures, in boiling hot springs or three miles underground in cracks in the rock.

Scientist Lynnae Quick, along with several other NASA scientists, looked at the likelihood of finding other life-bearing planets. This initial study contained a small sample of only 53 Earth-size planets. They specifically looked to see if the planets could support surface or subsurface oceans, as is the case with several moons in our own solar system. Of those, they calculated that 30 likely possess such bodies of water, more than half of the planets they analyzed. With a few billion Earth-size planets in our galaxy alone, that means there might be a lot of life-bearing planets out there. "Forthcoming missions will give us a chance to see whether ocean moons in our solar system could support life, said Quick.

The study didnt address the presence of intelligent aliens. There isnt enough data to decide that. But at least we have some idea of the possibilities now.

Planet Visibility Report

If youre up in the wee hours of Aug. 9, take a look at the southern sky between midnight and 1 a.m. The moon and the Red Planet, Mars, are separated by a mere three-finger widths held at arms length about 1/3 of the way up in the southeast. Jupiter and Saturn float less than a handspan apart in the southwest. Halfway between those two sits Pluto, but youll need a good-sized telescope to see it. Neptune is in the south, but, like Pluto, youll need a telescope to spot it.

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Stargazing: Astronomers estimate Earth-size planets number in the billions - Oklahoman.com

On June 10, thousands of academics around the globe halted their usual work to reflect on the systemic racism present in their fields and communities and plan ways to eradicate it. Scientific societies, universities and publishers joined in on the strike, which adopted the hashtags #ShutDownSTEM, #ShutDownAcademia and #Strike4BlackLives.

The strike, which occurred in the wake of the recent Black Lives Matter protests ignited by the murder of George Floyd, has brought conversations about the racism facing Black academics to the fore.

We recognize that our academic institutions and research collaborationsdespite big talk about diversity, equityand inclusionhave ultimately failed Black people, wrotemembers of Particles for Justice, one of the groups that organized the strike,in a statement. Black representation among physics faculty is non-existent at most institutions, and it is widely known that Black students often feel unwelcome, unsupportedand even unsafe in their physics departments and predominantly white campuses.

Black students face obstacles throughout academia, but many of these issues are particularly pronounced in physics. The figures paint a telling picture: Although the number of Black undergraduates earning bachelors degrees more than doubled between 1995 and 2015, in physics, the number of degrees awarded to Black studentsdropped from 5% in the late 1990s to 4% in recent years.

TEAM-UPa task force put together by the American Institute of Physics, a federation of physics societiesrecently completed a two-year study aimed at investigating the key factors stymieing the success of African American students in physics. The groups detailed findings and recommendations, which were published this January, provide insights as the scientific community grapples with ways to stamp out systemic racism in academia.

It has been heartening to see so many copies of the report downloaded from our website and for its recommendations to become part of our communitys dialog on racial justice in the physical sciences, says Arlene Modeste Knowles, TEAM-UPs project manager at AIP.

The TEAM-UP task force, which convened at the end of 2017, included two AIP staff members and 10 academics from various backgrounds, disciplines and career stages. Their study involved multiple lines of assessment, including surveys and interviews with students, visits to physics departments with a good track-record of attracting and retaining African American students, and an extensive review of the literature. The primary goal of the report was to provide a roadmap for community-wide efforts to double the number of bachelors degrees in physics and astronomy awarded to Black students by 2030.

Brian Beckford, a particle and nuclear physicist at the University of Michigan, says that one of his main reasons for joining the task force was that he believes that persistent underrepresentation of Black undergraduate students in physics is a solvable problem.

If we just takesome of the effort that we put into our experimentstrying to detect undetectable particles like neutrinos, searching for rare processesand we put it into trying to figure out solutions to a needed systemic change, we would be very far along in solving this, he says.

In their report, the task force concludes that Black students do not lack the drive, motivation, intellect or capabilities to obtain degrees in physics or astronomy. Instead, they are turning away from astronomy and physics because of a lack of supportive environments and because of the financial challenges facing both students and the departments that have consistently demonstrated the best practices in supporting their success.

The team pinpointed five key factors contributing to the success of African American students: belonging (feelings of inclusion or exclusion within a department), physics identity (students ability to perceive themselves as future physicists or astronomers), academic support (effective teaching, mentoring and strengths-based support that enables student success), personal support (means to lift the burden of financial stress, which disproportionally affect African American students) and leadership and structures (university departments prioritizing and creating supportive environments for African American students).

Beckford says that one of the responses he found most striking was a student who said they felta constant feeling that I am a representative, therefore I must be flawless.

Beckford says he has heard this time and time again from African American students hes mentoredand has felt it himself. I think its a culture issue that makes students feel this pressure to be exceptional, out of the fear that [their performance] reflects on every other student that may be given the opportunity to join the department, to get this fellowship, he says. Its quite a bit of pressure that theyre carrying around.

The task force provided specific recommendations about how to effectively address each of these factors. These include: creating and communicating norms that boost a students sense of belonging and eliminate identity-based harassment, providing services to African American students that focus on their strengths, and establishing a $50 million endowment to provide support for students facing financial hardship and for departments implementing the reports recommendations.

I hope that people will take away the important message that African American students are as capable of successfully earning their physics and astronomy bachelors degrees as other students ... [and] come to understand that the environment, cultureand available resources for these students must change in order to better support them, says Modeste Knowles. I hope that departments will be motivated to implement the recommendations so we can increase not only the number of African American bachelors degrees in physics and astronomy, but also the participation and success of African American students in these fields.

Although it is too early to assess the full impact of TEAM-UPs report, there are already signs that thegroups recommendations are being both considered and implemented.

Several institutionsincluding historically black colleges and universitiesare already practicing many of the recommendations in the report, and faculty members in physics and astronomy departments are reading and discussing the report with their colleagues, Modeste Knowles says.

Using funds provided by the Heising-Simons Foundation, the group now plans to run two workshops to discuss and share strategies to pursue the goal of doubling the number of African Americans earning bachelors degrees in physics and astronomy by 2030. Participants will include AIP and its affiliate societies, other scientific societies and faculty members from university physics and astronomy departments.

What I hope people take away from the report is that there are really no more excuses, Beckford says. The only thing left to do is act.

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Boosting the representation of Black students - Symmetry magazine

In the past few decades, the study of extrasolar planets has grown by leaps and bounds, with the confirmation of over 4000 exoplanets. With so many planets available for study, the focus of exoplanet-researchers is shifting from discovery to characterization. In the coming years, new technologies and next-generation telescopes will also enable Direct Imaging studies, which will vastly improve our understanding of exoplanet atmospheres.

To facilitate this process, astronomers will rely on costly technologies like coronagraphs and starshades, which block out the light of a star so any planets orbiting it will become more visible. However, according to a new study by an international team of astronomers and cosmologists, eclipsing binary stars could provide all the shading thats needed to directly image planets orbiting them.

The study, which recently appeared online, was led by Stefano Bellotti, a Ph.D. student at the LInstitut de Recherche en Astrophysique et Plantologie (IRAP) at the University of Toulouse. He was joined by researchers from the Centre National de la Recherche Scientifique (CNRS), the Steward Observatory, the National Astronomical Observatory of Japan (NAOJ), and NASAs Ames Research Center.

As the name would suggest, the Direct Imaging method consists of studying planets directly by analyzing light reflected from their surfaces and/or atmospheres. This method is rather lucrative when it comes to exoplanet studies since it allows astronomers to obtain spectra directly from a planets atmosphere, thus revealing its chemical composition and whether or not it could be habitable.

These and other benefits were spelled out by Bellotti who spoke to Universe Today via email. As he put it:

First of all, this method gives you a reliable yes or no answer: the planet (or planets) is there or it is not. Furthermore, because this method allows us to directly collect the light coming from a planet, we can directly examine the chemical composition of its atmosphere and have an idea of its features (clouds). Ultimately, this information enables us to assess the habitability of the planet, which is the current main focus of exoplanetary sciences.

However, this method presents a number of challenges since starlight is likely to be a billion times brighter than any light reflected from its planets. Scientists are able to reduce this discrepancy by an order of magnitude (where the stars appear 1 million times brighter) by examining reflected light in the infrared spectrum.

Because of these limitations, only 50 planets have been discovered using the Direct Imaging method to date. For the most part, these planets have been gas giants that have wide orbits around their stars. Astronomers anticipate that next-generation telescopes that rely on adaptive optics, coronagraphs, or an even an orbiting spacecraft (like NASAs proposed Starshade), will be able to image smaller, rocky planets that orbit closer to their planets.

For the sake of their study, however, Bellotti and his colleagues examined the potential for eclipsing binaries to do the same job, but without any of the expensive tools involved. As the name suggests, eclipsing binary systems consist of two stars that periodically pass in front of each other relative to the observer. When this happens, the brightness of one star in the system is temporarily blocked out, leading to a reduction in luminosity.

By using eclipsing binaries, explained Bellotti, astronomers can take advantage of the fact that the stellar system already undergoes periodic dimming which is predictable and can be timed accurately.

In this sense, the eclipse event suppresses the starlight coming from the binary in a natural way, and therefore results in an enhanced contrast between the binary and a potential planet. However, the eclipse event is not considered as a substitute of coronagraphs or artificial starshades, but it can be thought [of] as an additional tool to use along with them in order to achieve improved contrast levels. Indeed, because during [an] eclipse the binary system becomes point-like as a single star, techniques such as coronagraphy can be applied to block the light of the whole binary in one shot.

To test this, the team selected eclipsing binaries from several star catalogs whose luminosity drops by a factor of 10 during an eclipse. They also differentiated between types of exoplanets based on whether they emit their own light aka. self-luminous (SL) or reflect light (RL). They then simulated how bright orbiting planets would appear based on their mass, and whether or not theyd be visible using current or future telescopes.

Around two targets, [U Cephei] and [AC Scuti] respectively, we are [sensitive] to planets of roughly 4.5 Jupiter masses and 9 Jupiter masses with current ground- or near-future space-based instruments, and roughly 1.5 Jupiter masses and 6 Jupiter masses with future ground-based observatories (such as [the Extremely Large Telescope (ELT)], said Bellotti.

For reflected light planets, they selected three eclipsing binaries that were closest to Earth: V1412 Aquilae, RR Caeli, and RT Pictoris. For these systems, they used Jupiter, Venus, and Earth as templates for any possible exoplanets. Here too, they obtained some positive results.

We concluded that a Jupiter-like planet at a planet-star separation of 20 [milli arcseconds] might be imaged with future ground- and space-based technologies around all three targets, Bellotti added. A Venus-like planet at the same separation might be detectable around RR Cae and RT Pic, but a habitable Earth-like planet is challenging, as the planet-star separation is too small compared to the angular separation limit of modern coronagraphy.

In the coming years, ground-based observatories like the Extremely Large Telescope (ELT), the Thirty Meter Telescope (TMT), and the Giant Magellan Telescope (GMT) are expected to enable direct imaging studies of Earth-like exoplanets. Similarly, the James Webb Space Telescope (JWST) and Nancy Grace Roman Space Telescope (RST) will have cutting-edge infrared instruments that will also be able to study exoplanet atmospheres directly.

While these next-generation telescopes will have a better shot at observing exoplanets directly, it is encouraging to know that less-advanced observatories could still conduct direct imaging studies where eclipsing binaries are concerned. Whats more, these star systems could provide opportunities for advanced telescopes as well since they will be able to get a better look at exoplanets when their stars are eclipsed.

Further Reading: arXiv

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There are Natural Starshades Out There, Which Would Help Astronomers Image Exoplanets - Universe Today

Telescopes at the Next-Generation Transit Survey (NGTS) in Chile. Astronomers used these telescopes to find the lost world NGTS-11b. This image shows star trails; the bright streak is the moon. Image via University of Warwick.

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The habitable zone or Goldilocks zone around a star is of great interest to astrobiologists, those scientists probing for life beyond Earth. It is the region where temperatures on a rocky world are suitable for liquid water to exist. Astronomers have been discovering many exoplanets orbiting within habitable zones. But they wonder, just what percentage of exoplanets in our Milky Way galaxy might orbit within a habitable zone? In other words, what is the potential for life in our galaxy? Now, a new method devised and announced by scientists at the University of Warwick in the U.K. has found a cooler planet that had been previously lost close to its stars habitable zone. The planet is called NGTS-11b. These scientists say their method promises to help find many more such worlds orbiting in the habitable zones of their stars.

This rediscovery was published in the peer-reviewed journal The Astrophysical Journal Letters on July 20, 2020.

NGTS-11b is about the size and mass of Saturn. It orbits its star every 35 days. It is five times closer to its star than Earth is to the sun and is 620 light-years away.

Astronomers think that that it is just one of hundreds of lost worlds that this new technique can help rediscover.

Samuel Gill at the University of Warwick, lead author of the new study, is searching for lost worlds. Image via ResearchGate.

What do scientists mean by lost worlds?

Basically, they are exoplanets discovered by the Transiting Exoplanet Survey Satellite(TESS) space telescope but detected only once. TESS finds planets by observing them transit in front of their stars, but only scans most sections of the sky for 27 days. Any planets that have orbital periods longer than 27 days would only appear once in the observations. If a second observation cannot be obtained, the planet is considered lost as it were. But the researchers at the University of Warwick were able to reobserve some of these stars, using the Next-Generation Transit Survey (NGTS) in Chile, for up to 72 days. That way, planets with longer orbits could be detected. Thats how NGTS-11b was refound, by catching it transiting a second time. Samuel Gill, lead author of the paper, explained:

By chasing that second transit down weve found a longer period planet. Its the first of hopefully many such finds pushing to longer periods.

These discoveries are rare but important, since they allow us to find longer period planets than other astronomers are finding. Longer period planets are cooler, more like the planets in our own solar system.

NGTS-11b has a temperature of only 160 degrees Celsius (320 degrees Fahrenheit), cooler than Mercury and Venus. Although this is still too hot to support life as we know it, it is closer to the Goldilocks zone than many previously discovered planets which typically have temperatures above 1000 degrees Celsius (1800 F).

Co-author Daniel Bayliss said:

This planet is out at a thirty-five-day orbit, which is a much longer period than we usually find them. It is exciting to see the Goldilocks zone within our sights.

Artists illustration of the Transiting Exoplanet Survey Satellite (TESS). Some of the exoplanets found by TESS are categorized as lost when they cant be detected in a second transit of their star. Image via NASA/ Goddard Space Flight Center.

Another co-author,Pete Wheatley, added:

The original transit appeared just once in the TESS data, and it was our teams painstaking detective work that allowed us to find it again a year later with NGTS.

NGTS has twelve state-of-the-art telescopes, which means that we can monitor multiple stars for months on end, searching for lost planets. The dip in light from the transit is only 1% deep and occurs only once every 35 days, putting it out of reach of other telescopes.

The researchers expect that NGTS-11b will be just the first of hundreds of lost worlds found once again. Gill said:

There are hundreds of single transits detected by TESS that we will be monitoring using this method. This will allow us to discover cooler exoplanets of all sizes, including planets more like those in our own solar system. Some of these will be small rocky planets in the Goldilocks zone that are cool enough to host liquid water oceans and potentially extraterrestrial life.

Being able to detect multiple transits of a planet is crucial for determining its orbital period and mass, which cannot always be done by TESS alone. From the paper:

It is important to note that we have been able to determine the mass and radius of this relatively long-period exoplanet with a very modest number of radial-velocity measurements (nine with HARPS and six with FEROS). The detection of the second transit with NGTS was crucial for tightly constraining the possible orbital periods, and this serves to demonstrate the value of intense photometric monitoring in following up single-transit events. Without this second transit detection we would have required many more radial-velocity measurements in order to confirm the planet, determine its orbital period, and measure its mass (e.g., Daz et al. 2020). The strategy of large investments of photometric follow-up with instruments such as NGTS thereby allows efficient confirmation of single-transit events without adding to the considerable pressure on high-precision radial-velocity instruments. This highlights the power of high-precision ground-based photometric facilities in revealing longer-period transiting exoplanets that TESS alone cannot discover.

Many exoplanets discovered so far orbit very close to their stars, including hot Jupiters. Such objects are relatively easy to detect, but their nearness to their stars also makes them unlikely to be habitable. Finding more planets farther out from their stars, including those in their stars habitable zones, is important in the search for habitable worlds.

Telescopes like those at NGTS will help to find more habitable zone exoplanets, these scientists say.

Later, other telescopes like the upcoming James Webb Space Telescope now scheduled for launch in October 2021 will be able to analyze these planets atmospheres for possible biosignatures. By conducting research such as this, on Earth and in space, astronomers are stepping closer to finding other life in the galaxy, if it exists.

Artists concept of a gas giant planet orbiting its star. Researchers at the University of Warwick have rediscovered a planet about the size and mass of Saturn orbiting near the habitable zone of its star. Image via NASA/ JPL-Caltech.

Bottom line: Astronomers rediscover a previously lost exoplanet that is relatively cool and close to its stars habitable zone.

Source: NGTS-11 b (TOI-1847 b): A Transiting Warm Saturn Recovered from a TESS Single-transit Event

Via University of Warwick

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How astronomers rediscovered a lost world - EarthSky

Importantly, the missions primary purpose is to test and demonstrate the vehicles capability to safely carry crew to and from Earth orbit, as the first step in the plan of commencing regular ISS missions and commercial space flights.

The extreme velocities and temperatures the vehicle must endure present a major challenge to engineers and makes reentry the most perilous part of a mission.

The danger starts with finding the right angle of the trajectory as the spacecraft enters the upper atmosphere. If it is too steep, the astronauts will experience potentially fatal g-forces, and the friction of the air drag could cause the spacecraft to explode. If it is too shallow, the capsule will instead catastrophically skip off the atmosphere and back into Earth orbit.

The spacecraft will enter the upper atmosphere at 27,000km/hour. That is 7.5km/second, or more than 20 times the speed of sound. In whichever units you prefer this is fast. At these velocities, a very strong shock wave forms around the front of the vehicle, compressing and superheating the air. Managing the immense thermal load is a huge reentry engineering challenge.

At the most extreme stage, the temperature of the air in the shock layer exceeds 7,000C. By comparison, the temperature at the surface of the Sun is around 5,500C. This makes the vehicles heat shield so hot that it starts to glow a process called incandescence. SpaceXs new and advanced PICA-X material heat shield has managed to protect the capsule in test flights, later being recovered in a very charred state.

The air molecules around the vehicle also break down into positively charged atoms and free electrons a so-called plasma. When some of the molecules recombine, excess energy is released as photons (light particles) giving the air around the vehicle an amber glow.

This plasma layer may be beautiful, but it can cause radio blackouts. When an electron travels along a conductive wire, we have electricity. Similarly, when free electrons move through the plasma around the vehicle, we have an electric field. If the electric field becomes too strong, it can reflect and attenuate the radiowaves trying to reach the spacecraft.

Blackout not only leads to a loss of connection to on-board crew and flight data, it can also make remote control and guidance impossible. The Apollo missions, the Mars Pathfinder and the recent, failed 2018 Soyuz rocket launch all incurred communications blackout on the order of minutes. NASA mission control are anticipating a nervous six minutes of blackout during the peak heating phase of Crew Dragons return if anything goes wrong during this time, its in the hands of the astronauts.

Another risky stage is the parachute-assisted landing. The Crew Dragon will deploy four parachutes upon the final stage of reentry, as the vehicle descends toward a gentle splashdown in the Atlantic Ocean off the coast of Florida. This manoeuvre has been tested by SpaceX 27 times prior to next weeks crewed landing, so it should work.

A successful landing will have huge implications lowering the cost of space exploration through the use of reusable rockets and enabling private space exploration. While SpaceX engineered the Crew Dragon vehicle under contract to NASA, the company is free to use the spacecraft for commercial flights without NASA involvement after operational certification.

SpaceX has a partnership with commercial aerospace company Axiom Space, which has the ultimate goal of building the worlds first commercial space station. The proposed commercial activities for the station are broad: from in-space research and manufacturing to space exploration support.

Then there is space tourism. Private citizens are already queuing for their ticket to space, and with a successful Crew Dragon splashdown, they wont be waiting long. American space tourism company, Space Adventures (partnered with SpaceX), are planning to offer zero-gravity atmospheric flights, orbital flights with a spacewalk option and laps of the Moon by late 2021.

Whether the costs, environmental impact and dangers of spaceflight is justified for space tourism is debatable. As this articles shows, the required safety briefing for Space Adventure ticket holders will be much more comprehensive than your regular please take a moment to read the safety card in the seat pocket in front of you.

Heather Muir, PhD in Computational Physics, University of Cambridge

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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SpaceX: Crew Dragon is returning to Earth here's when to hold your - Astronomy Magazine

The Beachcomber published our article Should We Rename Maury Island? on July 16. We posed three options: topple the name Maury from our islands and find another name; rename Maury Island after a different Maury who does not carry the legacy of support for slavery; or, leave the name as it is and recognize the tarnished legacy William L. Maurys name carries.

In this piece, we explore Option 2, rename Maury Island after a different Maury who does not carry William L. Maurys tarnished legacy. This would accomplish something parallel to what happened here in 1986 when King County, which was originally named for William Rufus DeVane King (a senator from Alabama who enslaved people and was elected U.S. vice president in 1853 but died before serving in office) officially changed its eponym to the Rev. Dr. Martin Luther King Jr.

We want to suggest that Maury Island could remain Maury Island, but be named for Antonia Caetana Maury rather than William Lewis Maury. Antonia Maury was a remarkable early astronomer whose star classification system was adopted by the International Astronomical Union, was the first woman to publish in an astronomical observatory publication, and was one of the first to be awarded the Cannon Prize in Astronomy by the American Astronomical Society.

Antonia Maury, born in Cold Spring, New York on March 21, 1866, was the daughter of Protestant Reverend Mytton Maury and Virginia Draper and was a very distant cousin (second-cousin once-removed) of William L. Maury, after whom Maury Island was named in 1841. Antonia was the granddaughter of John William Draper, an astronomer who took the first detailed photograph of the moon in 1840, and a niece of astronomer Henry Draper, who pioneered star photography in the 1870s.

Antonia graduated from Vassar College in 1887 with honors in physics, astronomy, and philosophy. Edward Pickering, director of the Harvard College Observatory, hired her to be one of what was then termed women computers, analyzing light from stars as seen through the telescope and passed through a prism. Analysis of these spectral lines provides information about a stars temperature, chemistry and motion. Antonia was the Harvard Computer responsible for cataloging stellar spectra for bright stars in the northern hemisphere and was paid 25 cents an hour, less than half the amount paid to men.

Pickering and his staff had devised a simple alphabetical system for classification of stars, but Antonia independently found spectral patterns that did not fit into this system and devised her own more complex star classification. Her efforts to refine the spectral categories were not appreciated by Pickering. Doing original theoretical work conflicted with his expectations for her as a computer, and she left Harvard in 1891.

Before Antonia arrived at Harvard, Pickering had discovered the spectroscopic double, or binary, star Zeta Ursae Majoris; Antonias first task at the observatory was to determine its orbital period, and in 1889 she independently discovered a second spectroscopic binary, Beta Aurigae, and determined its orbit. Pickering wrote On the Spectrum of Zeta Ursae Majoris for the American Journal of Science in 1890; he noted briefly that The spectrum of this star has been photographed at the Harvard College Observatory on seventy nights and a careful study of the results has been made by Miss. A. C. Maury, a niece of Dr. Draper. There followed a detailed presentation of the results of that study, with no further mention of Antonia.

This slight weighed on Antonia and, when Pickering implored her to return to the Observatory or turn her work over to others, she wrote: I do not think it is fair that I should pass the work into other hands until it can stand as work done by me. I worked out the theory at the cost of much thought and elaborate comparison and I think that I should have full credit for my theory of the relations of the star spectra and also for my theories in regard to Beta Lyrae. Antonia returned to Harvard for a year in 1893 and again in 1895, to complete, using her own classifications, Spectra of Bright Stars Photographed with the 11-inch Draper Telescope, which was the first astronomical observatory publication credited to a woman, published in 1897.

She received further vindication of her insights in 1922 when the International Astronomical Union modified its classification system to adopt her classification methods, and in 1943 when she was awarded the Annie Jump Cannon Prize in Astronomy by the American Astronomical Society. She returned to the Harvard Observatory in 1918, after Pickerings death, and remained until her full retirement in 1948. In retirement, Antonia became an accomplished ornithologist and a passionate conservationist who fought to save western Sequoia forests. Antonia died on January 8, 1952.

In 1978, stellar astronomer William Wilson Morgan dedicated the Revised MK Spectral Atlas for Stars Earlier Than the Sun to Antonia C. Maury Master Morphologist of Stellar Spectra whom he also acclaimed as for me, the single greatest mind that has ever engaged itself in the field of the morphology of stellar spectra.

We plan to explore Option 1, topple the name Maury from our islands and find another name, in a subsequent article. One way that could happen is to consult with the descendants of the sHebabS Coast Salish Native People, the first people of Vashon Island, who were forcibly removed from our islands following the 1854 Treaty of Medicine Creek. We could ask them to suggest an appropriate name for Vashons sister island.

Steven C. Macdonald is a retired epidemiologist and a 20-year resident of Vashon Island. Bruce Haulman is an island historian.

Antonia Maury as a student at Vassar College (Courtesy Photo).

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Antonia: A Maury to be Proud Of - Vashon-Maury Island Beachcomber