Terraforming: It Wont Be Quite Like the Movies at First

When you think of astronauts on Mars, what comes to mind? Did you picture a red planet turning green with time and continued human colonization? Unfortunately, those days are far in the future, if they even happen at all. During the interview, Davis explained, Terraforming has a connotation of humans making another planetary body, like Mars, Earth-like. But really, its about humans changing their environment to make it more supportive of our need. What does this mean?

The first few trips to Mars will only include the essentials. One of NASAs first goals for its astronauts is to learn how to live on the planet. Since it differs greatly from Earth, survival is an important skill for astronauts to master. The initial base will probably include a habitat and a science lab. [The inside of] these modules will be much like the space station, but there will be differences. One example Davis gave included preventing toxic dust from getting into the habitat and lab. Microbial life is another threat to astronauts. Without more research on the planet, NASA cant say for certain what dangers could threaten human life. With this in mind, all scientists involved with the Mars mission will take these and other potential risks under consideration.

After the NASA base is well established and the astronauts learned survival basics, things get more interesting. Eventually, since it costs so much to send things from Earth, we will want to farm on Mars. Such a farm will really be green houses to protect the plants against the challenging Martian environment, said Davis. Keep in mind the Martian soil isnt like the soil on Earth. It lacks organics [the] rotting biological materials that plants need. Fortunately, it contains the minerals they require. Davis said that his team calls this soil regolith and it will need to be cleansed of some toxic materials. And NASA scientists can get the job done.

Detoxified soil isnt the only thing astronauts will need to grow plants. Theyll also need to utilize the water from Mars ice-capped poles. Davis said, Many anticipate that the first human base will be located adjacent to these billion-year-old ice deposits, so that humans can easily produce the volumes of water that they will need to support water intensive activities like farming. As of yet there is no word about which pole will be more beneficial, if theres a difference at all.

Before speaking to Davis, I believed that future Martian farms would be equivalent to greenhouses here on Earth. It seemed logical. Thats how people control plant growth here. However, while the plants will need a higher pressure to grow, the plants [dont] have to be [at] an Earth-like pressure. In fact, we can pressurize the greenhouse with carbon dioxide, which is the main component of the Martian atmosphere. This sounds like a win-win for both the scientists and the plants. Instead of the astronauts having to wear cumbersome space suits, they could just wear lightweight oxygen masks in the greenhouses. The key takeaway is that the planet doesnt have to transform into Earth2.0. Maybe one day it will, but for the time being, it just has to function for NASA scientists to live and work.

Time Will Tell

Mars has captured the imagination of humans for decades. These plans are just the next step in the process of getting the Mars Mission from the drawing room floor to a funded mission with a launch date. NASA isnt the only ones with their eyes on Mars. Others are already coming up with their own plans for the red planet. Scientists and enthusiasts have speculated on everything from nuking the planet into habitability to creating a magnetic shield around the planet to encourage it to grow its own atmosphere.

Mars is hopefully just our first step into the universe. Once weve dipped our toes out into the solar system, it will be easier to expand out into the asteroid belt and beyond. Mars low gravity provides the perfect platform for constructing and launching other deep space vehicles. After weve got that foothold, the only thing holding us back is our technology. As it is technology is the Achilles heal of the mission now. We might have a way to get to Mars before we have a means of safe exploration.

Those of us who have grown up watching the Apollo missions, space shuttles take-off and now the Falcon rockets climbing through the atmosphere likely wont see Mars colonized in our lifetimes, but that doesnt negate the wonder we all feel every time one of those rockets soars into the sky. Its not just a rocket, but a source of inspiration for generations to come one of which will step foot on Martian soil.

Megan Ray Nichols is a freelance science writer and the editor of Schooled By Science. When she isn't writing, Megan enjoys hiking, swimming and going to the movies. She invites you to follow her on LinkedIn and subscribe to her blog here.

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If we successfully land on Mars, could we live there? - Astronomy Magazine

Harold Weaver in 1981. (Woody Sullivan photo)

Harold Francis Weaver, a pioneer of radio astronomy who discovered the first microwave laser, or maser, in space, passed away peacefully in his Kensington, California, home on April 26 at the age of 99.

Weaver was a professor emeritus of astronomy, the founder of UC Berkeleys Radio Astronomy Laboratory and its director from 1958 until 1972 and a former chairman of the Department of Astronomy.

As a young astronomer at the University of Californias Lick Observatory near San Jose, and starting in 1951 as a member of the UC Berkeley astronomy faculty, Weaver became keenly aware of the potential of radio astronomy, which at the time was a young field. Many objects in space give off radio waves, from gas clouds and stars to galaxies, and today astronomers even observe microwave background radiation to infer the early history of the universe shortly after the Big Bang.

After several years of proposal writing, talking to administrators and searching for funds, Weaver founded the Radio Astronomy Laboratory in 1958. Two of his colleagues were Samuel Silver, a professor of electrical engineering and the namesake of the campuss Space Sciences Laboratory, and Luis Alvarez, a physicist and winner of the 1968 Nobel Prize in Physics.

Weaver when he was director of the Radio Astronomy Laboratory in the 1960s or 70s.

The lab dedicated its first telescopes, including an 85-foot dish at the time, one of the worlds largest in June 1962, in Hat Creek Valley in Northern California, far from radio noise that would have interfered with observations. Using the dish, Weaver and his colleagues discovered the first astrophysical maser microwave amplification by stimulated emission or radiation, the radio equivalent of a laser which had only been realized on Earth eight years earlier by the late UC Berkeley physicist and Nobel laureate Charles Townes.

At the time, many astronomers thought molecules could not exist in space, and the radio emissions Weaver recorded were attributed to an unknown form of interstellar matter named mysterium. But the emission was soon identified as coming from OH or hydroxyl molecules inside molecular clouds. Since then, many interstellar molecules have been found to emit coherent light in the form of a maser.

For decades, Weaver used the telescope to study other aspects of the interstellar medium and conducted large-scale surveys of interstellar hydrogen. The large telescope he built was destroyed by heavy winds in 1993, by which time Weavers successors were building smaller telescopes and assembling them in arrays to obtain even more sensitive measurements of radio emissions from space.

A gifted teacher, he mentored both undergraduate and graduate students, and occasionally taught seminars on archeoastronomy, the study of how ancient civilizations viewed and explained the changing night sky.

Harold was an outstanding thesis adviser, said one of Weavers former graduate students, Miller Goss, who went on to direct the Very Large Array of the National Radio Astronomy Observatory. His exacting counsel was invaluable. I learned many lessons that have stayed with me for the past 50 years. As I finished my thesis in early 1967, I will never forget sitting in the living room of the Weavers house with scissors as he taught me how to cut and paste in a pre-computer manner.

Among the many astronomers he mentored was Carl Sagan, whom he encouraged to explore his far-out ideas on the beginnings of life in the universe.

Weaver was born Sept. 25, 1917, in San Jose, where he lived with his parents above a spaghetti factory. After high school, as he was deciding whether to study astronomy or classics, Carmel poet Robinson Jeffers befriended him and encouraged his telescope building. Finally deciding to continue with astronomy, he went on to obtain his bachelors degree in 1940 and his Ph.D. in 1942 in astronomy from UC Berkeley.

After spending one year as a National Research Council postdoctoral fellow at Yerkes Observatory in Wisconsin, Weaver was conscripted into the war effort, working on optics with the National Defense Research Committee and later on isotope separation at the Berkeley Radiation Lab as part of the Manhattan Project.

As an undergraduate taking a course in practical astronomy, he met his future wife, Cecile Trumpler, daughter of UC Berkeley astronomer Robert Trumpler. They married in 1939, before the elder Trumpler supervised Weavers Ph.D. dissertation on peculiar stars, star clusters and stellar statistics based on observations at Mt. Wilson Observatory in Southern California.

After the war, Weaver returned to astronomy as a staff scientist at Lick Observatory from 1945 to 1951, when he joined the Berkeley faculty at a time when the departments focus was shifting from orbital calculations to stellar astrophysics. In 1953, Weaver and his father-in-law co-authored the book Statistical Astronomy.

Over Weavers career, he published more than 70 professional papers. He retired in 1988, but remained very much involved in the department until nearly the end of his life.

Harold came in every day until he was well into his 90s and was always a welcoming presence, said Leo Blitz, a professor emeritus of astronomy and former director of the Radio Astronomy Lab. He was never too busy or removed to talk about science, especially the implications of his groundbreaking survey of interstellar atomic hydrogen.

Harold was hidden away in his office in the old Campbell Hall almost daily, trying to map the local Bubble, the low-density region in interstellar space in which our sun and planets are located, said Imke de Pater, a professor and former chair of astronomy.

Weaver helped guide development of the Berkeley campus as a member and then chair of the Campus Facilities Committee in the 1950s and 60s, helping to design and name the new home of the astronomy department, Campbell Hall. The building was recently demolished and rebuilt on the same site.

Harold was truly a giant in our Department of Astronomy, said colleague Alex Filippenko. I will always remember his warm smile, his generosity and how he kept going with his research and other activities well into old age.

Harold was the wise voice of departmental memory always discreet, yet with biting insight, said Jon Arons, a professor emeritus and former chair of astronomy. He was a fascinating source of insight into radio astronomys early days, and what the Radio Astronomy Lab meant to the health of the department.

Weaver served as treasurer of the American Astronomical Society in the 1980s, and as treasurer of the Astronomical Society of the Pacific. He was part of the group that founded the Chabot Space and Science Museum and played an active role on its board for many years.

As a lover of music ranging from Mahler to the Beatles and Dave Brubeck, he also teamed up with David Williams and Tap Lum to found Berkshire Technologies, Inc., a company that made radio receivers that could pick up the faintest sounds. He also applied his interest in statistics to the stock market, working with Victor Nierderhofer on stock market modeling.

In addition to Weavers excitement about science, he was known for his kindness and his warm smile, his colleagues said. He and his wife, Cecile, organized numerous social events at their house, a tradition that has been continued by the Radio Astronomy Lab.

He is survived by his wife, three children Margot of Tucson, Arizona, Paul of Kensington and Kirk of Houston, Texas six grandchildren and 11 great-grandchildren. He and his wife donated their home in Kensington to the university to be used after their deaths to fund the Trumpler-Weaver Endowed Professorship of Astronomy at UC Berkeley.

A memorial service is being arranged. In lieu of flowers, the family requests that memorial gifts be made to the scholarship fund that enabled Weaver to attend college, the Cal Alumni Leadership Award. Donations should be sent to California Alumni Association, 1 Alumni House, Berkeley, CA 94720.

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Pioneering radio astronomer Harold Weaver dies at age 99 - UC Berkeley

May 2, 2017 Artist's illustration of the epsilon Eridani system showing Epsilon Eridani b, right foreground, a Jupiter-mass planet orbiting its parent star at the outside edge of an asteroid belt. In the background can be seen another narrow asteroid or comet belt plus an outermost belt similar in size to our solar system's Kuiper Belt. The similarity of the structure of the Epsilon Eridani system to our solar system is remarkable, although Epsilon Eridani is much younger than our sun. SOFIA observations confirmed the existence of the asteroid belt adjacent to the orbit of the Jovian planet. Credit: Illustration by NASA/SOFIA/Lynette Cook.

NASA's SOFIA aircraft, a 747 loaded with a 2.5-meter telescope in the back and stripped of most creature comforts in the front, took a big U-turn over the Pacific west of Mexico.

The Stratospheric Observatory for Infrared Astronomy aircraft was just beginning the second half of an overnight mission on Jan. 28, 2015. It turned north for a flight all the way to western Oregon, then back home to NASA's Armstrong Flight Research Center in Palmdale, California. Along the way, pilots steered the plane to aim the telescope at a nearby star.

Iowa State University's Massimo Marengo and other astronomers were on board to observe the mission and collect infrared data about the star.

That star is called epsilon Eridani. It's about 10 light years away from the sun. It's similar to our sun, but one-fifth the age. And astronomers believe it can tell them a lot about the development of our solar system.

Marengo, an Iowa State associate professor of physics and astronomy, and other astronomers have been studying the star and its planetary system since 2004. In a 2009 scientific paper, the astronomers used data from NASA's Spitzer Space Telescope to describe the star's disk of fine dust and debris left over from the formation of planets and the collisions of asteroids and comets. They reported the disk contained separate belts of asteroids, similar to the asteroid and Kuiper belts of our solar system.

Subsequent studies by other astronomers questioned that finding.

A new scientific paper, just published online by The Astronomical Journal, uses SOFIA and Spitzer data to confirm there are separate inner and outer disk structures. The astronomers report further studies will have to determine if the inner disk includes one or two debris belts.

Kate Su, an associate astronomer at the University of Arizona and the university's Steward Observatory, is the paper's lead author. Marengo is one of the paper's nine co-authors.

Marengo said the findings are important because they confirm epsilon Eridani is a good model of the early days of our solar system and can provide hints at how our solar system evolved.

"This star hosts a planetary system currently undergoing the same cataclysmic processes that happened to the solar system in its youth, at the time in which the moon gained most of its craters, Earth acquired the water in its oceans, and the conditions favorable for life on our planet were set," Marengo wrote in a summary of the project.

A major contributor to the new findings was data taken during that January 2015 flight of SOFIA. Marengo joined Su on the cold and noisy flight at 45,000 feet, above nearly all of the atmospheric water vapor that absorbs the infrared light that astronomers need to see planets and planetary debris.

Determining the structure of the disk was a complex effort that took several years and detailed computer modeling. The astronomers had to separate the faint emission of the disk from the much brighter light coming from the star.

"But we can now say with great confidence that there is a separation between the star's inner and outer belts," Marengo said. "There is a gap most likely created by planets. We haven't detected them yet, but I would be surprised if they are not there. Seeing them will require using the next-generation instrumentation, perhaps NASA's 6.5-meter James Webb Space Telescope scheduled for launch in October 2018."

That's a lot of time and attention on one nearby star and its debris disk. But Marengo said it really is taking astronomers back in time.

"The prize at the end of this road is to understand the true structure of epsilon Eridani's out-of-this-world disk, and its interactions with the cohort of planets likely inhabiting its system," Marengo wrote in a newsletter story about the project. "SOFIA, by its unique ability of capturing infrared light in the dry stratospheric sky, is the closest we have to a time machine, revealing a glimpse of Earth's ancient past by observing the present of a nearby young sun."

Explore further: Solar System's Young Twin Has Two Asteroid Belts

More information: Kate Y. L. Su et al, The Inner 25 au Debris Distribution in theEri System, The Astronomical Journal (2017). DOI: 10.3847/1538-3881/aa696b

(PhysOrg.com) -- Astronomers have discovered that the nearby star Epsilon Eridani has two rocky asteroid belts and an outer icy ring, making it a triple-ring system. The inner asteroid belt is a virtual twin of the belt in ...

Was it a catastrophic collision in the star's asteroid belt? A giant impact that disrupted a nearby planet? A dusty cloud of rock and debris? A family of comets breaking apart? Or was it alien megastructures built to harvest ...

When planets first begin to form, the aftermath of the process leaves a ring of rocky and icy material that's rotating and colliding around the young central star like a celestial roller derby. Analogs to our own Solar System's ...

(Phys.org)An international team of researchers reports the discovery of a series of concentric rings in the debris disk around a young nearby star known as HIP 73145. These unusual substructures could provide new details ...

Astronomers have successfully peered through the 'amniotic sac' of a star that is still forming to observe the innermost region of a burgeoning solar system for the first time.

In 1936, the young star FU Orionis began gobbling material from its surrounding disk of gas and dust with a sudden voraciousness. During a three-month binge, as matter turned into energy, the star became 100 times brighter, ...

(Phys.org)Russian scientists have presented the first results of solar observations made with the new radioheliograph of the Siberian Solar Radio Telescope (SSRT). The Siberian Radioheliograph (SRH), has recently commenced ...

VISTA's infrared capabilities have now allowed astronomers to see the myriad of stars in the Small Magellanic Cloud galaxy much more clearly than ever before. The result is this record-breaking imagethe biggest infrared ...

A mysterious gamma-ray glow at the center of the Milky Way is most likely caused by pulsars the incredibly dense, rapidly spinning cores of collapsed ancient stars that were up to 30 times more massive than the sun. That's ...

(Phys.org)Jason Wright, an astronomy professor at Penn State, has uploaded a paper to the arXiv preprint sever that addresses the issue of whether we have looked hard enough for extinct alien lifeparticularly intelligent ...

NASA's SOFIA aircraft, a 747 loaded with a 2.5-meter telescope in the back and stripped of most creature comforts in the front, took a big U-turn over the Pacific west of Mexico.

It was a good week for astrobiology. Within days of NASA's announcement that the necessary ingredients for life exist in the plumes erupting from the southern pole of Saturn's moon Enceladus, scientists gathered at Stanford ...

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Astronomers confirm nearby star a good model of our early solar system - Phys.Org

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Imy Hernandez, 5, of Throop, looks at Saturn during the Keystone College Thomas G. Cupillari 60 Astronomical Observatorys summer program on Wednesday. The program runs Mondays and Wednesdays through July 31. Jason Farmer / Staff Photographer photos/blumunkee

The heavenly bodies will be there. Whether youll be able to see them is another question.

The Lackawanna Astronomical Society will host Astronomy Day at Keystone Colleges Thomas G. Cupillari Observatory in Benton Twp. on Saturday starting at 7 p.m.

The observatorys telescopes and those of the astronomical societys members will be used to view the moon and its craters, mountains, seas and rills. The moon on Saturday will be in a waxing gibbous phase about three-quarters full.

Telescopes will also offer views of the solar systems largest planet, Jupiter, and its four largest moons. These are the moons first observed by Galileo, proving that some bodies orbit things other than the Earth.

Beyond the solar system, observations are planned of stars, star clusters, double stars, globular clusters and, possibly, nebulae.

Telescopes will be also be set up to safely view the sun before it sets over the western horizon.

The LAS said everyone is welcome, no reservations are required and admission is free.

Much depends on the weather, of course, and the extended forecast doesnt look promising. AccuWeather is calling for considerable clouds, occasional rain and drizzle in the evening, followed by a passing shower late. Saturdays high temperature is expected to be 56 and the overnight low 43.

Even if the weather doesnt cooperate, society members will be available to answer questions about their telescopes and observing the night sky. There will be an illustrated slide program and free sky maps, and free refreshments.

The observatory is at Route 107 and Hack Road in Fleetville, about 1 miles west of Interstate 81 Exit 202, and 7 miles from Keystones campus in La Plume Twp.

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Local astronomy club offers peek at the heavens - Scranton Times-Tribune

Searches for dark matter arent limited to facilities hundreds of feet underground. In the sky, astronomers continually seek observational evidence of the influence of dark matter on galactic scales. A recent study performed by an international team of astronomers, however, has proposed that the gamma ray glow coming from the Milky Ways center, previously attributed to dark matter, may not arise from so exotic a source. Instead, the study says, the gamma rays could be produced by pulsars.

The study, which has been submitted to The Astrophysical Journal, says that pulsars the rapidly spinning cores left behind by massive stars after they die are responsible for the gamma rays seen in the center of our galaxy. Using data from the Large Area Telescope on NASAs Fermi Gamma-ray Space Telescope, the researchers examined the central portions of the galaxy to determine the origin of the gamma-ray glow that has long been observed there. In a press release, Mattia Di Mauro of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) said, Our study shows that we dont need dark matter to understand the gamma-ray emissions of our galaxy. Instead, we have identified a population of pulsars in the region around the galactic center, which sheds new light on the formation history of the Milky Way.

Why was this glow previously thought to be a signal of dark matter? Although dark matter doesnt interact with normal matter directly, dark matter particles can decay or annihilate each other. Seth Digel, head of KIPACs Fermi group, explained: Widely studied theories predict that these processes would produce gamma rays. Thus, observers have searched for unexplained gamma rays in areas where dark matter is thought to accumulate, such as the centers of galaxies. And, indeed, the Milky Ways center is brighter in gamma-ray light than expected. Thus, one explanation for the excess radiation is reactions powered by dark matter.

But the galactic center is a challenging place to observe. Not only is it shrouded in dust, its also densely packed with stars and the home of energetic processes that could also explain the gamma-ray excess observed there. A significant portion of the glow is produced when cosmic rays resulting from supernovae hit the molecules in interstellar gas clouds, causing them to give off light. But pulsars can also inject energy into these gas clouds, causing them to glow as well.

And with the addition of this new data, Eric Charles of KIPAC explained, the gamma-ray excess at the galactic center is speckled, not smooth as we would expect for a dark matter signal. The speckles may be individual sources such as pulsars, which are small and hard to see, especially in such a crowded region in the galactic center. By contrast, a signal from dark matter should be smooth, following the general distribution of dark matter particles expected in the region.

Approximately 70 percent of the Milky Ways point sources are pulsars, Di Mauro said. And Pulsars have very distinct spectra that is, their emissions vary in a specific way with the energy of the gamma rays they emit. By modeling the gamma-ray glow expected from the specific emissions of pulsars, the group found that their expectations matched the observations, indicating that pulsars, not dark matter, is responsible.

The study is in agreement with some other findings, which show that gamma-ray signals attributable to dark matter in the centers of other galaxies, particularly dwarf galaxies, are not seen. While our neighbor, the Andromeda Galaxy, also shows a gamma-ray excess in its center, the group argues that it might be due to pulsars as well.

But the complexity of the centers of galaxies continues to make pinpointing the exact source of these gamma rays difficult, and the study cant completely rule out the possibility of dark matter as a contributor to the gamma-rays observed in the Milky Ways center. More direct evidence will be needed; the team is already planning to observe the area with radio telescopes to identify individual pulsars in an attempt to better characterize the origin of gamma rays in the Milky Ways bulge.

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How a hidden population of pulsars may leave the Milky Way aglow - Astronomy Magazine

Dark matter has a profound effect on our universe, shaping galaxies and even leaving its fingerprints on the energy left over from the Big Bang. Despite its relevance, dark matter is also extremely hard to detect rather than observe it directly, astronomers instead look for clues based on its gravitational interaction with normal matter (the protons, electrons, and neutrons that make up everything we see and touch). Recent observations made with NASAs Chandra X-ray Observatory have hinted that dark matter may be fuzzier than previously thought.

The study, which was recently accepted for publication in the Monthly Notices of the Royal Astronomical Society, focuses on X-ray observations of 13 galaxy clusters. The authors use observations of the hot gas that permeates galaxy clusters to estimate the amount and distribution of dark matter within the clusters and test its properties against current leading models, looking for the model that best fits the data.

The current standard cosmological model includes cold dark matter as a major component. In this case, cold simply means that dark matter travels slowly when compared to the speed of light. However, cold dark matter models indicate that dark matter and normal matter, which is drawn to the dark matter via gravity should clump together in the centers of galaxies. But no such increase in matter, normal or dark, is seen. Additionally, cold dark matter models predict that the Milky Way should have many more small satellite galaxies than we currently see. Even accounting for the fact that some satellites may be challenging to find, the cold dark matter models still over-predict our satellites by a considerable amount.

However, cold dark matter is only one of several dark matter theories. By contrast, fuzzy dark matter is a model in which dark matter has a mass about 10 thousand trillion trillion times smaller than an electron. In quantum mechanics, all particles have both a mass and a corresponding wavelength. Such a tiny mass would actually cause the wavelength of dark matter to stretch 3,000 light-years between peaks. (The longest wavelength of light, which is radio, stretches just a few miles between peaks.)

With a wavelength this long, dark matter would not clump in the centers of galaxies, which could explain the reason this is not observed. But while simple fuzzy dark matter models fit observations of small galaxies, larger galaxies may require a slightly more complex explanation. And galaxy clusters are larger test beds still, which is why researchers turned Chandra to several massive galaxy clusters for observations.

The results show that while a simple fuzzy dark matter model still didnt explain the cluster observations well, a more complex and fuzzier model did. In this model, dark matter occupying several quantum states at once (think an atom with many electrons, some of which are at higher energy levels) creates overlapping wavelengths that further spread out the effect, which changes the distribution of dark matter expected throughout the galaxy cluster as a whole.

The predictions from this model match the observations of the 13 galaxy clusters much more closely, indicating that fuzzier dark matter may be the best model to incorporate into our cosmological models. However, further study and more precise measurements are needed to better test this theory and ensure it truly reflect what we see throughout the cosmos.

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Dark matter may be fuzzier than we thought - Astronomy Magazine

This unprocessed image shows features in Saturns atmosphere from closer than ever before. The view of Saturns polar vortex was captured by NASAs Cassini spacecraft during its first Grand Finale dive past the planet on April 26, 2017. Credit: NASA/JPL-Caltech/Space Science Institute

NASAs Cassini spacecraft sped through a gap between Saturn and its rings for the second time Tuesday after data from the probes first perilous passage through the unexplored region last week found it to contain fewer potentially hazardous dust particles than expected.

The finding is one of several results from Cassinis first trip through the ring gap that has puzzled scientists.Engineers in charge of keeping Cassini safe, on the other hand, are pleased that the space between Saturn and its rings harbours fewer dangers.

The region between the rings and Saturn is the big empty, apparently, said Earl Maize, Cassini project manager at NASAs Jet Propulsion Laboratory in Pasadena, California. Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected.

Cassini radioed ground controllers April 27 that it safely made the first-ever flight through the 1,500-mile (2,400-kilometre) ring gap, coming closer to Saturn than any spacecraft in history.

The orbiter used its last flyby of Saturns largest moon Titan on April 22 to reshape its path around the planet, plunging Cassini on an orbit that will take it inside the rings once every week until Sept. 15, when it will dive into the ringed worlds hydrogen-helium atmosphere to end the mission.

Cassini made its second journey inside the rings Tuesday, and mission control at JPL received confirmation from the spacecraft around 1530 GMT (11:30 a.m. EDT) that it survived the encounter.

During last weeks flyby, Cassini turned to use its its 13-foot (4-metre) high-gain dish antenna as a shield to protect the spacecrafts sensitive components, like computers and scientific instruments, from the bombardment of any microscopic dust grains in its path.

Scientists crunching data captured last week said the passage produced far fewer dust impacts than predicted.

Models of the dust environment suggested Cassini would sail through the ring gap unscathed, so officials were not too concerned going into the first flyby. Nevertheless, recordings of the dust strikes were quieter than scientists expected.

The crafts radio and plasma wave science instrument detected hundreds of dust hits per second when Cassini was passing just outside Saturns rings over the last few months, but only registered a few impacts inside the ring gap.

Scientists converted the raw radio and plasma wave data into an audio format, NASA said, to listen for debris striking Cassinis antenna.

Dust particles hitting the instruments antennas sound like pops and cracks, covering up the usual whistles and squeaks of waves in the charged particle environment that the instrument is designed to detect, NASA said in a press release. The RPWS team expected to hear a lot of pops and cracks on crossing the ring plane inside the gap, but instead, the whistles and squeaks came through surprisingly clearly on April 26.

It was a bit disorienting we werent hearing what we expected to hear, said William Kurth, radio and plasma wave science team lead at the University of Iowa. Ive listened to our data from the first dive several times and I can probably count on my hands the number of dust particle impacts I hear.

Cassini made the trip through the ring gap at a relative velocity of about 77,000 mph (124,000 kilometres per hour), fast enough to travel from New York to Los Angeles in less than two minutes.

The video posted below includes the audio recording from Cassinis radio and plasma wave science instrument during the April 26 flyby.

The grains that hit Cassini were likely no bigger than a particle of smoke, or about 1 micron in size, according to NASA.

Cassinis swing inside Saturns rings Tuesday occurred without using the crafts antenna as a shield. Mission managers decided such a precaution was no longer necessary after sampling the dust during the first flyby.

But four of the 20 remaining ring gap passages will place Cassini closer to the inner edge of Saturns D ring, where scientists expect more dust particles. During those orbits, which begin in late May, the spacecraft will again turn its high-gain antenna into a shield.

Imagery from Cassinis approach to Saturn on April 26 revealed the closest-ever views of the planets clouds and a bizarre six-sided polar vortex scientists had only studied from afar before.

These images are shocking, said Kevin Baines, an atmospheric scientist on the Cassini team at JPL. We didnt expect to get anything nearly as beautiful as these images. All the different structures we see on them are phenomenal. We predicted wed see fogs and something pretty boring, but were seeing lots of great features a lot of activity going on on Saturn.

Baines called the hexagonal storm swirling at Saturns north pole the planets belly button.

This is a hole in the pole that is very deep, and we can tell that from looking at different colors of light, Baines said Friday in a Facebook Live event, comparing its structure to the behaviour of water in a flushing toilet. This is about 2,000 kilometres (1,200 miles) across.

Winds whip around the storm at up to 180 mph, or 300 kilometres per hour, Baines said. Like a hurricane on Earth, the wind speeds die down farther from the center of circulation, where individual storm clouds appear to move around Saturn in the planets jet stream.

Now we see structure, Baines said. You see the curly cues on here, all sorts of strange features that were trying to understand Now were seeing little tiny circular clouds that really have their own individual characters.

They might (have) convective upwelling from below, so were looking for lightning and other things to see if we can really confirm that, Baines said.

(For) this first dive, were focusing on looking at Saturn, said Linda Spilker, Cassinis project scientist at JPL. We got a series of images from the pole to the equator. We have other data as well, spectra in the infrared, the far-infrared and ultraviolet that will help us put together the puzzle of what were seeing.

During the missions second orbit through the ring gap, Cassinis cameras were programmed to take pictures of Saturns rings backlit by the sun, a viewing geometry that allows the instruments to see faint ringlets and other fine structures.

Future encounters will focus on studying Saturns interior, magnetic field and taking the first measurement of the mass of the planets rings, which will tell scientists about their age and origin.

The video posted below condenses one hour of observations into an animated movie showing a series of Cassini images taken April 26.

The movie shows Cassinis view of Saturn starting from an altitude of 45,000 miles to just 4,200 miles (72,400 kilometers to 6,700 kilometers) above the planets cloud tops.

I was surprised to see so many sharp edges along the hexagons outer boundary and the eye-wall of the polar vortex, said Kunio Sayanagi, an associate of the Cassini imaging team based at Hampton University in Virginia, who helped produce the new movie. Something must be keeping different latitudes from mixing to maintain those edges.

The images from the first pass were great, but we were conservative with the camera settings. We plan to make updates to our observations for a similar opportunity on June 28 that we think will result in even better views, said Andrew Ingersoll, a member of the Cassini imaging team based at Caltech.

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[ 3 May 2017 ] NASA probe finds Saturn ring gap emptier than predicted News - Astronomy Now Online

Todays astronomers dont really look at stars or galaxies so much as images produced from data generated by light. If that same data were used to produce 3-D printouts, tactile displays or sound, would it open the study and pursuit of astronomy to the blind and visually impaired?

Thats the kind of question the University of Chicagos Yerkes Observatory and its partners will try to answer with the help of a $2.5 million National Science Foundation grant. Over the next three years, they will develop Afterglow Accessnew software that will make astronomy more accessible to the blind and visually impaired.

Amazing pictures of stars start as numbers on a spreadsheet, and those numbers can be manipulated and presented in myriad ways, said Kate Meredith, director of education outreach at the Yerkes Observatory and the education lead of Innovators Developing Accessible Tools for Astronomy, a new research initiative from the observatory. We wont consider ourselves successful unless within three years we have developed new computer tools with and for the blind and visually impaired that can be used in real applications, learning situations and scholarly research.

The National Federation of the Blind estimates that more than seven million Americans are visually disabled. Unequal access to quantitative information and the lack of vision-neutral tools presents them with barriers to study and master astronomy and other STEM subjects, Meredith said.

To overcome this, the Yerkes research initiative will engage blind and visually impaired students as well as sighted students and their teachers from mainstream and specialized schools for the blind. Twenty teachers and 200 eighth- through 12th-grade students are expected to participate annually. Recruiting teachers and students began this spring. While half of the participating schools will be located in southern Wisconsin and the Chicago area, the remaining schools will be selected from across the United States and its territories.

Students and teachers will participate in user-centered design and universal design processes to develop and test software and learning modules and to improve accessibility aspects of astronomy tools for educational and professional purposes. The project builds upon the success of prior National Science Foundation-supported research projects, including the development of Afterglow; Quorum, an accessible programming language; and the Skynet Junior Scholars, a program that supports collaborative astronomy investigations by young explorers using Skynets international network of telescopes.

The research will advance knowledge about student learning related to computational thinking, the role of computation in astronomy and software design. In addition, it will help determine how participation influences student attitudes and beliefs about who can engage in computing and STEM subjects.

Teaming up blind and visually impaired students with sighted students, teachers and professionals in the design and development of astronomy software and instructional modules will create powerful educational experiences, encourage STEM learning, and lower the barrier-to-entry for blind and visually impaired individuals interested in astronomy and related careers, Meredith said.

Investigators in the program include employees at the University of Chicago; Yerkes Observatory; Associated Universities Inc.; the Technical Education Research Center at the University of Nevada, Las Vegas; and Skynet at the University of North Carolina at Chapel Hill.

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Students, teachers craft software to make astronomy accessible to the blind - UChicago News

A wave spanning 200,000 light-years (about twice the size of our Milky Way Galaxy) is rolling through the Perseus Cluster, according to observations from NASAs Chandra X-ray Observatory coupled with radio observations and computer simulations.

This X-ray image of the hot gas in the Perseus Cluster was made from 16 days of Chandra observations. An oval highlights the location of an enormous wave found to be rolling through the gas. Image credit: NASAs Goddard Space Flight Center / Stephen Walker et al.

Galaxy clusters are the largest structures bound by gravity in the Universe today.

Approximately 11 million light-years across and located 240 million light-years away, the Perseus Cluster (Abell 426) is named for its host constellation.

Like all galaxy clusters, most of its observable matter takes the form of a pervasive gas averaging tens of millions of degrees, so hot it only glows in X-rays.

Observations from NASAs Chandra X-ray Observatory have revealed a variety of structures in this gas, from vast bubbles blown by the supermassive black hole in the clusters central galaxy, NGC 1275, to an enigmatic concave feature known as the bay.

The bays concave shape couldnt have formed through bubbles launched by the black hole.

Radio observations using the Karl G. Jansky Very Large Array show that the bay structure produces no emission, the opposite of what astronomers would expect for features associated with black hole activity.

In addition, standard models of sloshing gas typically produced structures that arc in the wrong direction.

A team of astronomers led by Dr. Stephen Walker of NASAs Goddard Space Flight Center turned to existing Chandra observations of the Perseus Cluster to further investigate the bay.

The scientists combined a total of 10.4 days of high-resolution data with 5.8 days of wide-field observations at energies between 700 and 7,000 electron volts. For comparison, visible light has energies between about two and three electron volts.

The authors then filtered the Chandra data to highlight the edges of structures and reveal subtle details.

Next, they compared the edge-enhanced Perseus image to computer simulations of merging galaxy clusters.

One simulation seemed to explain the formation of the bay.

In it, gas in a large cluster similar to Perseus has settled into two components, a cold central region with temperatures around 54 million degrees Fahrenheit (30 million degrees Celsius) and a surrounding zone where the gas is three times hotter.

Then a small galaxy cluster containing about a thousand times the mass of the Milky Way skirts the larger cluster, missing its center by around 650,000 light-years.

The flyby creates a gravitational disturbance that churns up the gas like cream stirred into coffee, creating an expanding spiral of cold gas.

After about 2.5 billion years, when the gas has risen nearly 500,000 light-years from the center, vast waves form and roll at its periphery for hundreds of millions of years before dissipating.

These waves are giant versions of Kelvin-Helmholtz waves, which show up wherever theres a velocity difference across the interface of two fluids, such as wind blowing over water. They can be found in the ocean, in cloud formations on Earth and other planets, in plasma near Earth, and even on the Sun.

We think the bay feature we see in Perseus is part of a Kelvin-Helmholtz wave, perhaps the largest one yet identified, that formed in much the same way as the simulation shows, said Dr. Walker, who is the lead author of the paper reporting the results in the Monthly Notices of the Royal Astronomical Society (arXiv.org preprint).

We have also identified similar features in two other galaxy clusters, Centaurus and Abell 1795.

The team also found that the size of the waves corresponds to the strength of the clusters magnetic field.

If its too weak, the waves reach much larger sizes than those observed. If too strong, they dont form at all.

This study allowed astronomers to probe the average magnetic field throughout the entire volume of these clusters, a measurement that is impossible to make by any other means.

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S.A. Walker et al. 2017. Is there a giant Kelvin-Helmholtz instability in the sloshing cold front of the Perseus cluster? MNRAS 468 (2): 2506-2516; doi: 10.1093/mnras/stx640

This article is based on text provided by NASAs Goddard Space Flight Center.

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Astronomers Find Enormous Wave of Hot Gas Rolling through Nearby Galaxy Cluster - Sci-News.com