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Is Planet 9 The Missing Super-Earth

October 19, 2017 by  
Filed under Around The Net

Planet Nine is out there, and astronomers are determined to find it, according to a new statement from NASA. In fact, mounting evidence suggests it’s hard to imagine our solar system without the unseen world. 

The hypothetical planet is believed to be about 10 times more massive than Earth and located in the dark, outer reaches of the solar system, approximately 20 times farther from the sun than Neptune is. While the mysterious world still has yet to be found, astronomers have discovered a number of strange features of our solar system that are best explained by the presence of a ninth planet, according to the NASA statement. 

“There are now five different lines of observational evidence pointing to the existence of Planet Nine,” Konstantin Batygin, a planetary astrophysicist at the California Institute of Technology (Caltech) in Pasadena, said in the statement. “If you were to remove this explanation and imagine Planet Nine does not exist, then you generate more problems than you solve. All of a sudden, you have five different puzzles, and you must come up with five different theories to explain them.”

In 2016, Batygin and co-author Mike Brown, an astronomer at Caltech, published a study that examined the elliptical orbits of six known objects in the Kuiper Belt, a distant region of icy bodies stretching from Neptune outward toward interstellar space. Their findings revealed that all of those Kuiper Belt objects have elliptical orbits that point in the same direction and are tilted about 30 degrees “downward” compared to the plane in which the eight official planets circle the sun, according to the statement. 

Using computer simulations of the solar system with a Planet Nine, Batygin and Brown also showed that there should be even more objects tilted a whopping 90 degrees with respect to the solar plane. Further investigation revealed that five such objects were already known to fit these parameters, the researchers said. 

Since then, the astronomers have found new evidence that further supports the existence of Planet Nine. With help from Elizabeth Bailey, an astrophysicist and planetary scientist at Caltech, the team showed that Planet Nine’s influence might have tilted the planets of our solar system, which would explain why the zone in which the eight major planets orbit the sun is tilted by about 6 degrees compared to the sun’s equator.

“Over long periods of time, Planet Nine will make the entire solar-system plane precess, or wobble, just like a top on a table,” Batygin said in the statement. 

Finally, the researchers demonstrate how Planet Nine’s presence could explain why Kuiper Belt objects orbit in the opposite direction from everything else in the solar system. 

“No other model can explain the weirdness of these high-inclination orbits,” Batygin said in the statement. “It turns out that Planet Nine provides a natural avenue for their generation. These things have been twisted out of the solar system plane with help from Planet Nine and then scattered inward by Neptune.”

Going forward, the researchers plan to use the Subaru Telescope at Mauna Kea Observatory in Hawaii to find Planet Nine, and then deduce where the mysterious world came from. 

The most common type of planets discovered around other stars in our galaxy has been what astronomers call “super Earths” — rocky worlds that are larger than Earth but smaller than Neptune. However, no such planet has yet been discovered in our solar system, meaning that Planet Nine could be our missing “super Earth,” the researchers said. 

Follow Samantha Mathewson @Sam_Ashley13. Follow us @Spacedotcom, Facebook

 

Courtesy-Space

Does Proxima Centauri b Have A Shiny Green Tint

October 17, 2017 by  
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A world orbiting the sun’s closest stellar neighbor may have a shiny green tint to it — and not necessarily because it’s covered in leafy plants. 

Researchers have found a way to characterize potential auroras on the nearby exoplanet Proxima Centauri b and found that, if the planet sports oxygen in its atmosphere, the auroras may give the atmosphere a greenish cast. 

“The northern and southern lights [on Proxima Centauri b] would be at least 100 times brighter than on Earth,” Rodrigo Luger, a postdoctoral student at the University of Washington, who led the study of how the planet’s auroras could be spotted from Earth, told Space.com by email. Luger said the auroras might be so bright as to be visible with very powerful telescopes.

The active star Proxima Centauri lies only 4.2 light-years from the solar system. A small world orbits in the star’s habitable zone, the region where liquid water could survive on the surface. Its radius remains a mystery. However, scientists know it is about 1.3 times as massive as the Earth, which its initial discovers said suggests a rocky planet. 

Proxima Centauri is a small star, dimmer than Earth’s sun, so its habitable zone is closer to the star than the habitable zone of the sun. As a result, Proxima Centauri b is 20 times closer to its star than Earth is to the sun, and completes an orbit every 11.2 Earth-days. The red dwarf star is more active than Earth’s sun, firing off far more frequent flares that may douse the planet in radiation that could be harmful for potential life. 

Those same flares may help scientists better understand the planet. If Proxima Centauri b has a magnetic field, it may capture the charged particles in the flares and funnel them toward the poles, creating brilliant auroral displays. 

Observing the auroras can help researchers characterize the planet’s atmosphere. On Earth, the different color glow of the northern and southern lights corresponds to reactions with different molecules in the atmosphere. According to Luger, who presented the results at the Astrobiology Science Conference in Mesa, Arizona, in April, if Proxima Centauri b is a terrestrial world with an Earth-like atmosphere and a magnetic field, the green light of the oxygen auroras would grow 100 times stronger than on Earth.

Because of the potential for green light, the researchers dubbed such a world “the pale green dot,” a nod to Carl Sagan’s categorization of Earth as a pale blue dot.

Periods of intense stellar activity could make the auroras even brighter. While coronal mass ejections and flares have the strongest impact on generating auroras, Luger said, they aren’t really predictable in advance.

“But the sun certainly has periodic activity cycles, so if we understand those of Proxima Centauri, we might be able to use that to our advantage,” he said.

He went on to say that the extreme activity of the star may make such knowledge unnecessary — astronomers could simply count on a high likelihood that the star would flare and cause the auroras to brighten.

While several studies have described searches for auroras on gas giant exoplanets that orbit close to their parent stars, none have been spotted on worlds beyond the solar system. But Luger remains confident.

“Proxima Centauri b is optimal for auroral detection,” he said.

He gave several reasons that auroras may be soon spotted on Proxima Centauri b. The planet is nearby — it’s the closest known exoplanet to Earth — making it easier for instruments to collect detailed observations. The extreme magnetic activity of the star, coupled with the planet’s close orbit, means Proxima Centauri b is bombarded with solar particles far more vigorously than Earth. At the same time, the star is faint, so a glowing green planet would show up more easily than it would around a sun-like star. Finally, the short orbit means that the world moves around its sun at a rapid clip; when a light source is moving toward or away from an observer, this motion can be observed through a phenomenon called redshift, or Doppler shift. Luger said the Doppler shift of the auroras’ light waves would be significantly larger than they would be on their own, making lines that would otherwise be hard to see more visible. That would make it easier to identify any oxygen in the atmosphere.

Unfortunately, this “pale green dot” won’t be spotted with current telescopes. NASA’s upcoming powerhouse telescope ― the James Webb Space Telescope ― will hunt for infrared light, so Luger said it won’t be able to detect the green oxygen aurora, which is in the visible light range.

“Our best bet for detection is the [Thirty-Meter Telescope] or similar next-generation extremely large telescopes,” he said.

The Thirty-Meter Telescope (TMT) — so-named because its primary mirror would be 30 meters (98 feet) wide — began construction on Hawaii’s Mauna Kea peak before it was halted in 2015 after protests over the sacred nature of the land. The project remains at a halt today, though some astronomers have lauded the benefits of moving the telescope to Spain’s Canary Islands.

But even TMT would take some time to identify the signature of oxygen from the auroras, with Luger estimating “tens of hours” of observation. The same is true for the Large UV/Opitcal/Infrared Survey (LUVOIR), a proposed design for a telescope with a primary mirror between 9 and 15 meters (30 and 50 feet). With telescope time extremely competitive, it could be hard to study the system so extensively.

In order to produce auroras, a planet must have a magnetic field. Out of the four terrestrial planets in Earth’s solar system, only two have a worldwide field — Earth and Mercury. Mars has a patchy field, and Venus has none. If Proxima Centauri b is similarly lacking, it might not produce auroras.

However, the planet may get a brightness boost from airglow, the faint emission of light from the atmosphere that keeps nighttime on Earth from ever being completely dark.

“The planet is likely also to have strong airglow, which is planetwide,” Luger said. “Airglow is not generated by magnetic fields, and is typically weaker than aurorae, so we did not calculate it. But it should be quite strong on Proxima Centauri b, and could cause the entire planet to glow green.”

Courtesy-Space

Astronomers Discover Water Mystery On Mars

October 9, 2017 by  
Filed under Around The Net

A new examination of old data suggests that there might be ice hiding in the Martian equator, even though scientists previously thought that the substance couldn’t exist there.

Scientists uncovered an unexpected amount of hydrogen when looking at older data from NASA’s Mars Odyssey spacecraft dating back to between 2002 and 2009. At higher latitudes, hydrogen generally indicates buried water ice, but this was not believed possible at the equator, according to a statement from NASA.

If there is indeed water there, this would help with a future human mission to Mars, because it could mean the astronauts wouldn’t need to bring the substance with them for drinking, cooling equipment or watering plants, researchers said in the statement. Instead, the astronauts could live off the land to an extent, reducing the number of resources that need to be trucked (at higher cost) from Earth

Mars Odyssey’s first major discovery, in 2002, was also linked to water; the spacecraft found buried hydrogen at high latitudes, and the 2008 landing of the Phoenix Mars lander confirmed that there was water ice. However, at lower latitudes, measurements of hydrogen were explained as hydrated minerals (which other spacecraft have also observed). Researchers didn’t think water ice was thermodynamically stable in those areas.

For this new study, the researchers analyzed data collected using Mars Odyssey’s neutron spectrometer. The instrument is not designed to directly detect water, but by measuring neutrons, it can detect signatures of hydrogen, which can mark the presence of water or other hydrogen-bearing substances. 

The science team reduced the blurring or “noise” in Odyssey’s data using image-reconstruction techniques based on those used for other spacecraft and for medicine, according to the statement. This improved the spatial resolution of the data to 180 miles (290 kilometers), twice the previous resolution of 320 miles (520 km).

“It was as if we’d cut the spacecraft’s orbital altitude in half, and it gave us a much better view of what’s happening on the surface,” Jack Wilson, the study’s principal investigator and a postdoctoral researcher at the Johns Hopkins University Applied Physics Laboratory.

Their work focused on equatorial areas, particularly in zones around the Medusae Fossae formation, an area that includes material that is easy to erode. Previous observations from NASA’s Mars Reconnaissance Orbiter and the European Space Agency’s Mars Express orbiter suggested there might be volcanic deposits or water ice just below the surface. Scientists, however, were skeptical that it was water ice, because “if the detected hydrogen were buried ice within the top meter [3.3 feet] of the surface, there would be more than would fit into pore space in soil,” Wilson said.

The study’s scientists emphasized that more evidence is needed to conclude that the signature indeed comes from water ice. They’re not too sure how the water was preserved, they said; perhaps ice and dust flowing from the poles moved through the atmosphere when Mars had a steeper axis tilt than today. However, it’s been at least hundreds of thousands of years since those conditions existed, and the water ice deposited back then shouldn’t be around anymore, the researchers said. (This would be true even if, somehow, dust or a crust at the surface trapped the humidity underground, the scientists added.)

“Perhaps the signature could be explained in terms of extensive deposits of hydrated salts, but how these hydrated salts came to be in the formation is also difficult to explain,” Wilson said. “So, for now, the signature remains a mystery worthy of further study, and Mars continues to surprise us.”

Courtesy-Space

Astronomers Discover Prehistoric Lake On Mars Could Have Supported Life

October 6, 2017 by  
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An up-close view of Mars’ rocky deposits by NASA’s Curiosity rover shows a changing climate in the planet’s ancient past that would have left the surface warm and humid enough to support liquid water — and possibly life. Evidence of an ancient lake points to the prospect of two unique habitats within its shores; the lower part of the lake was devoid of oxygen compared to an oxygen-rich upper half. 

In a recent paper published in the journal Science, Redox stratification of an ancient lake in Gale crater,” Stony Brook University geoscientist Joel Hurowitz and his colleagues used more than three years of data retrieved from the rover to paint a picture of ancient conditions at Gale Crater, the lowest point in a thousand kilometers. The site, a 150-mile kilometer crater formed during an impact around 3.8 billion years ago, once flowed with rivers ending in a lake. The sedimentary rocks laid down by these rivers and onto the lakebed tell the story of how the environment changed over time.

Curiosity landed on a group of sedimentary rocks known as the Bradbury group. The rover sampled a part of this group called the Sheepbed mudstones, as well as rocks from the Murray formation at the base of the 5-kilometer high peak at the center of the crater known as Mount Sharp. Both types of rocks were deposited in the ancient lake, but the Sheepbed rocks are older and occur lower in the stratigraphic layers of rocks. Comparing the two types of rocks can lead to interesting revelations about the paleoenvironment. 

Rocks that form at the same time in the same area can nevertheless display differences in composition and other characteristics. These different groupings are known as “facies” and the Murray formation is split into two facies. One is comprised mainly of hematite and phyllosilicate, and given the name HP, while the other is the magnetite-silicate facies, known as MS. 

“The two Murray facies were probably laid down at about the same time within different parts of the lake,” explained Hurowitz. “The former laid down in shallow water, and the latter in deeper water.”

The near-shore HP facies have thicker layers in the rocks compared to the thin layers of the deeper water MS facies. This difference in layer thickness is because the river flowing into the lake would have slowed down and dumped some of its sedimentary material at the lake shore. The flow would then have spread into the lake and dropped finer material into the deeper parts of the lake. 

Curiosity landed on rocks known as the Bradbury group. The Murray formation consist of younger rocks at the base of Mount Sharp. The height is exaggerated in the diagram.

The different mineralogy of the two facies was caused by the lake becoming separated into two layers. Ultraviolet (UV) radiation along with low levels of atmospheric oxygen penetrated the upper part of the lake and acted as oxidants on molecules in the water. These ions of iron (Fe2+) and manganese (Mn2+) were brought to the lake via seepage of groundwater through the lake floor.

When the UV and oxygen interacted with these, they lost electrons, meaning that they had become “oxidized.” The oxidized iron and manganese precipitated into minerals — hematite and manganese oxide — that eventually made up the rocks sampled by Curiosity in the HP facies. However, the UV and oxygen didn’t reach all the way to the lake floor, so the iron and manganese wasn’t oxidized in the deeper part of the lake, and instead became the mineral known as magnetite, making up the MS facies. 

The difference in oxidation of the two facies in the Murray formation due to differences in layers of the lake is known as redox stratification. Identifying redox stratification in the ancient lake shows that there were two completely different types of potential habitat available to any microbial life that might have been present.

The researchers also discovered that the Murray formation has a high concentration of salts, which provide clues relating to evaporation of the lake, and thus the end of the potential habitat. High salinity is a result of water evaporating and leaving salts behind. However, evaporation leaves other tell-tale signs such as desiccation cracks — similar to what you see when mud dries and cracks — and none of these signs appear in the Murray formation. This indicates that the evaporation occurred at a later period of time and that the salts seeped through layers overlying the Murray formation before becoming deposited in the Murray rocks. 

“Curiosity will definitely be able to examine the rocks higher up in the stratigraphy to determine if lake evaporation influenced the rocks deposited in it,” said Hurowitz. “In fact, that’s exactly what the rover is doing as we speak at the area known as Vera Rubin Ridge.”

Once Curiosity examines these rocks, it will be able to confirm that the salts found in the Murray formation came from a later period of evaporation, and therefore no significant evaporation occurred during the time that the Murray formation was deposited, meaning the environment would have been stable enough to support possible life forms.

The inflowing river deposits thicker material (clastics) close to the lake shore, and finer material towards the deeper part of the lake. The incoming UV and O2 oxidizes the iron and manganese in the upper part

Another result of the research is evidence of climate change. The older Sheepbed formation shows very little evidence of chemical weathering compared to the Murray formation. The change to substantial chemical weathering in the younger rocks indicates that the climate likely changed from cold, arid conditions to a warm, wet one. 

“The timing of this climate shift is not something we can tell for sure because we haven’t seen the Sheepbed member and the Murray formation in contact with each other,” said Hurowitz. “If we had, then we might be able to tell if the change in their chemical and mineralogical properties were abrupt (indicating rapid climate change) or gradual. At best, what we can say is that the rocks that we examined were likely deposited over a timespan of tens of thousands of years to as much as around 10 million years.”

The cause of the climate change on Mars is still a matter of debate. If the climate changed in a short period of time, it could have been due to short-term variations or an asteroid impact. A slower change in climate could have been the result of changes in the obliquity cycle of the planet.

The climate change indicated in the rocks shows that the ancient Martian environment would have been warm and humid enough to sustain liquid water on the surface. The redox stratification of the lake as revealed by the different mineralogy in the Murray formation shows that there would have been two different environments within the lake itself. If microbial life was present on Mars at this time, the different potentially habitable niches could have encouraged diversity with anaerobic forms possibly living in the lower depths of the lake. 

“I’m not sure that this was something we would have predicted if we hadn’t had the opportunity to examine Gale’s rock record up close and personal,” adds Hurowitz.

Courtesy-Space

 

Astronomers Find Two Black Holes At The Center Of A Spiral Galaxy

September 29, 2017 by  
Filed under Around The Net

Not one but two gigantic black holes lurk at the heart of the distant spiral galaxy NGC 7674, a new study suggests.

These two supermassive black holes are separated by less than 1 light-year and together harbor about 40 million times the mass of the sun, researchers said.

If it holds up, the find would be just the second known system of double supermassive black holes. The other, announced in 2006, is in a galaxy known as 0402+379, whose two giant black holes are separated by about 24 light-years and boast a combined 15 billion solar masses.  

(The Laser Interferometer Gravitational-Wave Observatory project, or LIGO, has spotted the gravitational waves emitted by multiple binary black holes as they spiral toward each other. But the LIGO detections involve objects a few tens of times more massive than the sun, known as stellar-mass black holes.)

The research team analyzed observations of NGC 7674, which lies about 400 million light-years from Earth, that were made by the Very Large Array, a network of radio telescopes in New Mexico. The researchers found two distinct, compact sources of radio-wave emission at the galaxy’s center.

“The two radio sources have properties that are known to be associated with massive black holes that are accreting gas, implying the presence of two black holes,” study lead author Preeti Kharb, of the National Centre for Radio Astrophysics at the Tata Institute of Fundamental Research in India, said in a statement.

These two behemoths orbit their common center of mass about once every 100,000 years, the researchers said.

The two newfound black holes probably sidled up when their former host galaxies merged to form the current NGC 7674. (Most, if not all, galaxies are thought to have supermassive black holes at their centers.) This supposition is bolstered by the twisted, Z-like shape of the galaxy’s radio emission — a large-scale structure thought to be produced by a galaxy collision, study team members said.

“Detection of a binary supermassive black hole in this galaxy also confirms a theoretical prediction that such binaries should be present in so-called Z-shaped radio sources,” co-author David Merritt, of the Rochester Institute of Technology in New York, said in the same statement.

Courtesy-Space

Astronomers Find Carbon Star With Red Glowing Bubble

September 28, 2017 by  
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Gorgeous new imagery shows the enormous, glowing bubble that a strange, dying red star has blown around itself.

The huge star, known as U Antliae, lies about 900 light-years from Earth, in the southern constellation Antlia (the Air Pump). U Antliae has burned all the hydrogen and helium in its core and has therefore moved on to the “asymptotic giant branch” (AGB), the last major step in the life cycle of a sun-like star before it becomes superdense white dwarf. 

AdvertisementA few millennia ago, U Antliae erupted in a spasm of activity that generated a big bubble, a surprisingly thin structure that astronomers have now studied using the European Southern Observatory’s Atacama Large Millimeter/submillimeter Array (ALMA), a network of radio telescopes in northern Chile.

“Around 2,700 years ago, U Antliae went through a short period of rapid mass loss,” ESO officials wrote in a statement. “During this period of only a few hundred years, the material making up the shell seen in the new ALMA data was ejected at high speed. Examination of this shell in further detail also shows some evidence of thin, wispy gas clouds known as filamentary substructures.”

ALMA captured the bubble in multiple wavelengths of light, producing a 3D “data cube” that researchers have mined in detail. For example, the imagery shows gases in the bubble moving toward or away from the observer at different speeds, ESO officials said.

This image was created from ALMA data on the red carbon star U Antliae and its surrounding shell of material. The colors show the motion of the glowing material in the shell along the line of sight to the Earth. Blue material lies between us and the central star, and is moving toward us. Red material around the edge is moving away from the star, but not toward Earth. (For clarity, this view does not include the material on the far side of the star, which is receding from us in a symmetrical manner.)

Analyzing such stellar bubbles could help astronomers better understand the evolution of stars and galaxies, ESO officials added.

“Shells such as the one around U Antliae show a rich variety of chemical compounds based on carbon and other elements,” the officials wrote in the same statement. “They also help to recycle matter and contribute up to 70 percent of the dust between stars.”

The new ALMA imagery is part of a study, led by Franz Kerschbaum of the University of Vienna, that has been accepted for publication in the journal Astronomy & Astrophysics.

Courtesy-Space 

Does The Asteroid Belt Hold Key To The Building Blocks Of Planets

September 27, 2017 by  
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The asteroid belt may have started out empty, later becoming a “cosmic refugee camp” taking on leftovers of planetary formation from across the solar system, a new study finds.

The main asteroid belt, located between the orbits of Mars and Jupiter, makes up 0.05 percent the mass of Earth. The asteroids there can range greatly in mass, with the four largest ones — Ceres, Vesta, Pallas and Hygiea — holding more than half the belt’s mass.

To explain the dramatic range of sizes in the asteroid belt, previous models suggested that the primordial asteroid belt originally possessed a mass equal to at least that of Earth, and that its members had less disparity in mass. The gravitational pulls of the planets later helped whittle down this primordial belt, depleting asteroids of certain sizes more than others.  

However, these prior models of asteroid formation raised a question: how the belt could have lost more than 99.9 percent of its mass without losing all of it, said study lead author Sean Raymond, an astronomer at the University of Bordeaux in France.

“Our approach is the opposite. We asked the question, ‘Could the asteroid belt have been born empty?’,” Raymond told Space.com. “The answer is yes, effortlessly.”

The scientists developed computer models of an empty primordial asteroid belt to see whether leftovers from planetary formation could explain the belt’s current composition. The inner belt is dominated by dry S-type, or silicaceous, asteroids, which appear to be made of silicate materials and nickel iron and account for about 17 percent of known asteroids. The outer belt is dominated by water-rich C-type, or carbonaceous, asteroids, which consist of clay and stony silicate rocks and make up more than 75 percent of known asteroids.

The researchers found that an empty primordial asteroid belt could explain the mass and compositions of the current members of the asteroid belt. This model suggests that this zone between Mars and Jupiter is a repository of planetary leftovers, “a refugee camp housing objects that were kicked out of their homes and left to brave interplanetary space, finally settling onto stable orbits in the asteroid belt,” Raymond told Space.com. 

In this new model, the inner belt consists largely of rocky leftovers from the formation of the terrestrial planets — Earth, Mars, Venus and Mercury. In contrast, the outer belt is made up of remnants of the formation of the gas giant planets, such as Jupiter and Saturn.

“In terms of composition, Jupiter and Saturn grew in a region that was much colder than where the rocky planets grew,” Raymond said. “Being colder, their cores could incorporate ice and other volatiles. The C-types are about 10 percent water, whereas the S-types are much drier, having started off in the much hotter terrestrial planet zone.”

These findings suggest that the asteroid belt “is a treasure trove — it must contain relics of the building blocks of all the planets,” Raymond said. “There must be pieces of terrestrial building blocks out in the asteroid belt, as well as leftovers from building the giant planets’ cores.”

Future research can further test how well the various models of asteroid-belt formation match reality. Raymond hopes the team’s new concept “will help keep people’s minds open to potentially drastically different origins stories for the solar system, and for extra-solar planets, too.”

Raymond and his colleague Andre Izidoro at the University of Bordeaux detailed their findings online Sept. 13 in the journal Science Advances.

Courtesy-Space

Is NASA Planning Another Mission To Saturn

September 26, 2017 by  
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Humanity’s light at Saturn has gone out.

NASA’s robotic Cassini spacecraft burned up in the ringed planet’s atmosphere Friday morning (Sept. 15), ending a remarkable 13-year run at Saturn that has revolutionized scientists’ understanding of the outer solar system and its potential to host life.

For example, Cassini discovered methane seas on Saturn’s huge moon Titan and geysers of water vapor blasting from fellow moon Enceladus. Both of these moons are worthy of much further study, as is the ringed planet itself and the diverse Saturn system as a whole, Cassini team members said. 

“We left the world informed, but still wondering, and I couldn’t ask for more,” Cassini project manager Earl Maize, of NASA’s Jet Propulsion Laboratory in Pasadena, California, said during a news conference Wednesday (Sept. 13). “We’ve got to go back — we know it.”

And various research teams are indeed working on plans to return to Saturn. In fact, five such concepts are in the running for NASA’s next New Frontiers mission — the same type flown by the agency’s New Horizons Pluto probe, Juno Jupiter orbiter and OSIRIS-REx asteroid sample-return craft.

During its intentional death dive Friday, Cassini briefly became the first-ever Saturn atmospheric probe. One of the proposed New Frontiers missions would pick up on, and greatly extend, the last measurements Cassini ever made.

The SPRITE (Saturn Probe Interior and Atmosphere Explorer) spacecraft would plunge into Saturn’s thick atmosphere, characterizing its composition and structure for about 90 minutes before breaking apart and burning up. (Cassini, which was not built for such work, lasted just a minute or two during its dive.)

“Fundamental measurements of the interior structure and noble-gas abundances of Saturn are needed to better constrain models of solar system formation, as well as to provide an improved context for exoplanet systems,” principal investigator Amy Simon, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and her colleagues wrote in a mission description last year.

SPRITE would make such measurements, and its data would help “ground-truth” data Cassini gathered about Saturn from afar over the years, the scientists added

Cassini studied Titan closely over the course of 127 targeted flybys. The Saturn orbiter also carried a piggyback European lander called Huygens, which touched down on the 3,200-mile-wide (5,150 kilometers) moon in January 2005. In the process, it became the first probe ever to pull off a soft landing on a body in the outer solar system.

Observations by both Cassini and Huygens revealed Titan in all its otherworldly glory. Hydrocarbon rain falls from the huge moon’s sky, pooling in lakes and seas of methane, some of which are as big as Earth’s Black Sea. Complex organic chemicals — the carbon-containing building blocks of life as we know it — waft about in Titan’s thick, nitrogen-dominated atmosphere and eventually drift down to the moon’s surface.

It’s possible that this bizarre landscape could harbor life, astrobiologists say. And Cassini’s work suggests that the big moon may have another potentially habitable environment as well: a salty ocean of liquid water buried beneath the crust. (Indeed, Cassini was directed to its doom primarily to ensure that it would never contaminate Titan or Enceladus with microbes from Earth.)

A proposed New Frontiers mission called Oceanus would investigate both of these environments, taking a variety of measurements from its perch in orbit around Titan. For example, the probe would characterize the organics in the moon’s atmosphere and help researchers determine how thick and rigid Titan’s crust is, and whether it is convecting internal heat to the surface.

Oceanus “would follow up on Cassini’s amazing discoveries and assess Titan’s habitability by following the organics through the methanologic cycle and assessing exchange processes between the atmosphere, surface and subsurface,” the concept mission’s planners wrote in a description of the project, which they presented earlier this year at the 48th Lunar and Planetary Science Conference in The Woodlands, Texas.

Also in the New Frontiers running is Titan Dragonfly, which would send a drone to study the moon from the air and the ground.

“Heavier-than-air flight is substantially easier [on Titan]” than on Earth, Dragonfly principal investigator Elizabeth Turtle, a planetary scientist at the Johns Hopkins University Applied Research Laboratory in Maryland, told Space.com earlier this year. (Titan’s atmosphere is considerably thicker than that of Earth, but the moon’s gravity is just 14 percent as strong as our planet’s.)

“That means we can take a really capable lander and move it by a few tens of kilometers in a single flight, and hundreds of kilometers over the time of the mission,” Turtle added.

The drone would study the composition of Titan’s organics in detail, at a variety of different locations.

“Dragonflyis a truly revolutionary concept providing the capability to explore diverse locations to characterize the habitability of Titan’s environment, investigate how far prebiotic chemistry has progressed, and search for chemical signatures indicative of water-based and/or hydrocarbon-based life,” Turtle and her colleagues wrote about the potential mission in their presentation at the 48th Lunar and Planetary Science Conference.

The other two Saturn-oriented New Frontiers proposals target 313-mile-wide (504 km) Enceladus, whose geysers were a revelation to the Cassini team, NASA officials and space scientists in general.

“When we observed the southern hemisphere [of Enceladus] and geysers of water spewing out into the Saturn system, it amazed us and began changing the way we view the habitability — or potential habitability — of moons in the outer part of our solar system,” Jim Green, chief of NASA’s Planetary Science Division at the agency’s headquarters in Washington, D.C., said at Wednesday’s news conference.

That’s because the water in Enceladus’ geysers is apparently coming from an ocean of liquid water that sloshes beneath the frigid moon’s icy crust. Cassini observations suggest that this ocean may even have a chemical energy source that could support life as we know it.

But researchers want to learn more about the ocean, and the geysers’ plume provides a great way of doing so. One of the New Frontiers candidates, known as Enceladus Life Finder (ELF), would zoom through this plume repeatedly, collecting and analyzing molecules. ELF would look for complex organic compounds that could be a sign of prebiotic chemistry — or perhaps even of life itself.

“It’s free samples,” principal investigator Jonathan Lunine, of Cornell University, told Space.com in 2015, when ELF was competing for a slot in NASA’s Discovery program of low-cost, extremely focused missions. (In January of this year, NASA chose the asteroid-studying Lucy and Psyche missions as its next Discovery projects.) “We don’t need to land, drill, melt or do anything like that.” 

Cassini did some plume sampling of its own, but ELF would sport more-sensitive mass spectrometers than its predecessor did, ELF team members have said. (Cassini’s handlers didn’t know about Enceladus’ geysers before launch, so they didn’t put any life-hunting gear aboard the craft.)

Not much has been publicly revealed about the final Saturn-oriented New Frontiers proposal. But its name — Enceladus Life Signatures and Habitability — suggests that it would also be a plume-sampling mission.

You can learn more about all 12 New Frontiers candidates — the other seven of which would target Venus, a comet or Earth’s moon — in this excellent synopsis by The Planetary Society’s Van Kane.

NASA is expected to cull the New Frontiers proposals to a handful of finalists before the end of the year and announce the selected mission sometime in 2019. (That mission will have a cost cap of $850 million, excluding launch, and will lift off by 2025.)

So, it’s too soon to say if any of the Saturn-centric missions will ever get off the ground. But fans of the ringed planet may be heartened by one of Green’s comments at Wednesday’s news conference.

Cassini’s discoveries “will live on for many decades afterwards, and already they’re beckoning us to go back,” Green said. Between NASA’s Voyager mission, which visited Saturn with back-to-back flybys in 1980 and 1981, “and Cassini was 30 years,” he said, “and I believe that will be much shorter the next time around.”   

 

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Astronomers Ponder The Role Of Physics In Life

September 25, 2017 by  
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Understanding the origin of life is arguably one of the most compelling quests for humanity. This quest has inevitably moved beyond the puzzle of life on Earth to whether there’s life elsewhere in the universe. Is life on Earth a fluke? Or is life as natural as the universal laws of physics?

Jeremy England, a biophysicist at the Massachusetts Institute of Technology, is trying to answer these profound questions. In 2013, he formulated a hypothesis that physics may spontaneously trigger chemicals to organize themselves in ways that seed “life-like” qualities.

Now, new research by England and a colleague suggests that physics may naturally produce self-replicating chemical reactions, one of the first steps toward creating life from inanimate substances.

This might be interpreted as life originating directly from the fundamental laws of nature, thereby removing luck from the equation. But that would be jumping the gun.

Life had to have come from something; there wasn’t always biology. Biology is born from the raw and lifeless chemical components that somehow organized themselves into prebiotic compounds, created the building blocks of life, formed basic microbes and then eventually evolved into the spectacular array of creatures that exist on our planet today.  

“Abiogenesis” is when something nonbiological turns into something biological and England thinks thermodynamics might provide the framework that drives life-like behavior in otherwise lifeless chemicals. However, this research doesn’t bridge life-like qualities of a physical system with the biological processes themselves, England said.

“I would not say I have done anything to investigate the ‘origin of life’ per se,” England told Live Science. “I think what’s interesting to me is the proof of principle – what are the physical requirements for the emergence of life-like behaviors?”

Self-organization in physical systems

When energy is applied to a system, the laws of physics dictate how that energy dissipates. If an external heat source is applied to that system, it will dissipate and reach thermal equilibrium with its surroundings, like a cooling cup of coffee left on a desk. Entropy, or the amount of disorder in the system, will increase as heat dissipates. But some physical systems may be  sufficiently out of equilibrium that they “self-organize” to make best use of an external energy source, triggering interesting self-sustaining chemical reactions that prevent the system from reaching thermodynamic equilibrium and thus maintaining an out-of-equilibrium state, England speculates. (It’s as if that cup of coffee spontaneously produces a chemical reaction that sustains a hotspot in the center of the fluid, preventing the coffee from cooling to an equilibrium state.) He calls this situation “dissipation-driven adaptation” and this mechanism is what drives life-like qualities in England’s otherwise lifeless physical system.

A key life-like behavior is self-replication, or (from a biological viewpoint) reproduction. This is the basis for all life: It starts simple, replicates, becomes more complex and replicates again. It just so happens that self-replication is also a very efficient way of dissipating heat and increasing entropy in that system.

In a study published July 18 in the journal Proceedings of the National Academy of Sciences,  England and co-author Jordan Horowitz tested their hypothesis. They carried out computer simulations on a closed system (or a system that doesn’t exchange heat or matter with its surroundings) containing a “soup” of 25 chemicals. Although their setup is very simple, a similar type of soup may have pooled on the surface of a primordial and lifeless Earth. If, say, these chemicals are concentrated and heated by an external source – a hydrothermal vent, for example – the pool of chemicals would need to dissipate that heat in accordance with the second law of thermodynamics. Heat must dissipate and the entropy of the system will inevitably increase.

Under certain initial conditions, he found that these chemicals may optimize the energy applied to the system by self-organizing and undergoing intense reactions to self-replicate. The chemicals fine-tuned themselves naturally. These reactions generate heat that obeys the second law of thermodynamics; entropy will always increase in the system and the chemicals would self-organize and exhibit the life-like behavior of self-replication.

“Essentially, the system tries a bunch of things on a small scale, and once one of them starts experiencing positive feedback, it does not take that long for it to take over the character of organization in the system,” England told Live Science.

This is a very simple model of what goes on in biology: chemical energy is burned in cells that are – by their nature – out of equilibrium, driving the metabolic processes that maintain life. But, as England admits, there’s a big difference between finding life-like qualities in a virtual chemical soup and life itself.

Sara Imari Walker, a theoretical physicist and astrobiologist at Arizona State University who was not involved in the current research, agrees.

“There’s a two-way bridge that needs to be crossed to try to bridge biology and physics; one is to understand how you get life-like qualities from simple physical systems and the other is to understand how physics can give rise to life,” Imari Walker told Live Science. “You need to do both to really understand what properties are unique to life and what properties are characteristic of things that you consider to be almost alive […] like a prebiotic system.”

Emergence of life beyond Earth?

Before we can even begin to answer the big question of whether these simple physical systems may influence the emergence of life elsewhere in the universe, it would be better to understand where these systems exist on Earth first.

“If, when you say ‘life,’ you mean stuff that is as stunningly impressive as a bacterium or anything else with polymerases and DNA, my work doesn’t yet tell us anything about how easy or difficult it is to make something that complex, so I shouldn’t speculate about what we’d be likely to find elsewhere than Earth,”  England said. (Polymerases are proteins that assemble DNA and RNA.)

This research doesn’t specifically identify how biology emerges from nonbiological systems, only that in some complex chemical situations, surprising self-organization occurs. These simulations do not consider other life-like qualities – such as adaptation to environment or reaction to stimuli. Also, this thermodynamics test on a closed system does not consider the role of information reproduction in life’s origins, said Michael Lässig, a statistical physicist and quantitative biologist at the University of Cologne in Germany.

“[This] work is indeed a fascinating result on non-equilibrium chemical networks but it is still a long way from a physics explanation of the origins of life, which requires the reproduction of information,” Lässig, who was not involved in the research, told Live Science.

There’s a critical role for information in living systems, added Imari Walker. Just because there appears to be natural self-organization exhibited by a soup of chemicals, it doesn’t necessarily mean living organization.

“I think there’s a lot of intermediate stages that we have to get through to go from simple ordering to having a full-on information processing architecture like a living cell, which requires something like memory and hereditary,” said Imari Walker. “We can clearly get order in physics and non-equilibrium systems, but that doesn’t necessarily make it life.”

To say England’s work could be the “smoking gun” for the origin of life is premature, and there are many other hypotheses as to how life may have emerged from nothing, experts said. But it is a fascinating insight into how physical systems may self-organize in nature. Now that researchers have a general idea about how this thermodynamic system behaves, it would be a nice next step to identify sufficiently out-of-equilibrium physical systems that naturally occur on Earth, England said.

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Astronomers Find Titanium Oxide On Aline Planet

September 22, 2017 by  
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For the first time ever, titanium oxide has been spotted in an exoplanet’s skies, a new study reports.

Astronomers using the European Southern Observatory’s Very Large Telescope (VLT) in Chile detected the substance in the atmosphere of WASP-19b, a huge, scorching-hot planet located 815 light-years from Earth.

The presence of titanium oxide in the atmosphere of WASP-19b can have substantial effects on the atmospheric temperature structure and circulation,” study co-author Ryan MacDonald, an astronomer at the University of Cambridge in England, said in a statement.  

One possible effect is “thermal inversion.” If enough titanium oxide is present, the stuff can keep heat from entering or exiting an atmosphere, causing upper layers to be hotter than lower layers, researchers said. (This phenomenon occurs in Earth’s stratosphere, but the culprit is ozone, not titanium oxide.)

Artist’s illustration showing the exoplanet WASP-19b, whose atmosphere contains titanium oxide. In large enough quantities, titanium oxide can prevent heat from entering or escaping an atmosphere, leading to a “thermal inversion” in which temperatures are higher in the upper atmosphere than lower down.

WASP-19b is a bizarre world about the mass of Jupiter. The alien planet lies incredibly close to its host star, completing one orbit every 19 hours. As a result, WASP-19b’s atmospheric temperatures are thought to hover around 3,600 degrees Fahrenheit (2,000 degrees Celsius).

The research team — led by Elyar Sedaghati of the European Southern Observatory, the German Aerospace Center and the Technical University of Berlin — studied WASP-19b for more than a year using the VLT’s refurbished FORS2 instrument. These observations allowed them to determine that small amounts of titanium oxide, along with water and wisps of sodium, swirl around in the exoplanet’s blistering air.

“Detecting such molecules is, however, no simple feat,” Sedaghati said in the same statement. “Not only do we need data of exceptional quality, but we also need to perform a sophisticated analysis. We used an algorithm that explores many millions of spectra spanning a wide range of chemical compositions, temperatures, and cloud or haze properties in order to draw our conclusions.”

In addition to shedding new light on WASP-19b, the new study — which was published online today (Sept. 13) in the journal Nature — should improve researchers’ modeling of exoplanet atmospheres in general, team members said.

“To be able to examine exoplanets at this level of detail is promising and very exciting,” said co-author Nikku Madhusudhan, also of the University of Cambridge. 

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With Boron On Mars Prove Life Once Existed

September 21, 2017 by  
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NASA’s Mars rover Curiosity has discovered boron in Gale Crater — new evidence that the Red Planet may have been able to support life on its surface in the ancient past.

Boron is a very interesting element to astrologists; on Earth, it’s thought to stabilize the sugary molecule ribose. Ribose is a key component of ribonucleic acid (RNA), a molecule that’s present in all living cells and drives metabolic processes. But ribose is notoriously unstable, and to form RNA, it is thought that boron is required to stabilize it. When dissolved in water, boron becomes borate, which, in turn, reacts with ribose, making RNA possible.

In a new study published in the journal Geophysical Research Letters, researchers analyzed data gathered by Curiosity’s ChemCam (Chemistry and Camera) instrument, which zaps rocks with a powerful laser to see what minerals they contain. ChemCam detected the chemical fingerprint of boron in calcium-sulfate mineral veins that have been found zigzagging their way through bedrock in Gale Crater, the 96-mile-wide (154 kilometers) crater that the rover is exploring. These veins were formed by the presence of ancient groundwater, meaning the water contained borate.

The find raises exciting possibilities, the researchers said.

“Because borates may play an important role in making RNA — one of the building blocks of life — finding boron on Mars further opens the possibility that life could have once arisen on the planet,” study lead author Patrick Gasda, a postdoctoral researcher at Los Alamos National Laboratory in New Mexico, said in a statement. 

“Borates are one possible bridge from simple organic molecules to RNA,” he added. “Without RNA, you have no life. The presence of boron tells us that, if organics were present on Mars, these chemical reactions could have occurred.”

Scientists have long hypothesized that the earliest “proto-life” on Earth emerged from an “RNA World,” where individual RNA strands containing genetic information had the ability to copy themselves. The replication of information is one of the key requirements for basic lifelike systems. Therefore, the detection of boron on Mars, locked in calcium-sulfate veins that we know were deposited by ancient water, shows that borates were present in water “0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit) and with neutral-to-alkaline pH,” the researchers said.

“We detected borates in a crater on Mars that’s 3.8 billion years old, younger than the likely formation of life on Earth,” Gasda added. “Essentially, this tells us that the conditions from which life could have potentially grown may have existed on ancient Mars, independent from Earth.”

Since landing on Mars in 2012, Curiosity has uncovered compelling evidence that the planet used to be a far wetter place than it is now. For example, the rover has found evidence of a lake-and-stream system inside Gale Crater that lasted for long stretches in the distant past. And, by climbing the slopes of Mount Sharp — the 3.4-mile-high (5.5 km) mountain in the crater’s center — Curiosity has been able to examine various layers of sedimentary minerals that formed in the presence of ancient water. 

These studies are helping scientists gain a better understanding of how long these minerals were dissolved in the water, where they were deposited and, ultimately, how they impacted the habitability of the Red Planet. The detection of boron is another strand of evidence supporting the idea that ancient life might have existed on our neighboring planet.

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Astronomers Discuss The Phenomena Of Black Holes

September 20, 2017 by  
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Paul Sutter is an astrophysicist at The Ohio State University and the chief scientist at COSI Science Center. Sutter is also host of Ask a Spaceman, We Don’t Planet, and COSI Science Now. Sutter contributed this article to Space.com’s Expert Voices: Op-Ed & Insights.

I think it’s time for everyone to admit that black holes are annoying. Out there, drifting around the galaxy — with their much bigger cousins lurking in the centers of those galaxies — black holes are the ultimate paradoxes of nature, silently mocking our feeble attempts to understand them.

By all accounts, black holes should not exist, and for a long time, they were shrugged off as mere mathematical artifacts — an annoying bug in the otherwise elegant machinery of general relativity.

The German physicist Karl Schwarzschild was the first to “discover” black holes. In 1915, he devised a solution for general relativity applicable to the simple (i.e., nonrotating, uncharged, boring) case of a perfectly spherical object embedded in otherwise empty space. While this sounds a tad idealized, the setup is close enough to real scenarios like our own solar system that it can be quite useful.

I put “discover” in quotation marks because Schwarzchild didn’t jump out of the trenches of the Eastern Front (where, while not solving fantastically complicated equations, he was fighting the Russians during World War I), exclaiming that he’d found a new astrophysical object. But buried in his mathematics were the hints of something … darker.

Those hints take the form of what we now call the Schwarzschild radius and the singularity. Every object has a Schwarzschild radius assigned to it, and that number is determined by the object’s mass. Within this radius, the behavior of gravity starts to get a little weird. But that’s fine, because in almost all cases, the radius is very, very (very, very, very) small compared to the object itself, and rests far inside it. For example, our sun is about 870,000 miles (1.4 million kilometers) across, and it boasts a Schwarzschild radius of … 1.9 miles (3 km).

The fact that gravity behaves weirdly inside the Schwarzschild radius is nothing to sweat: For one, we really only care about the gravity outside the object, and two, we know other physical processes will take over and swamp any gravitational weirdness inside that radius.

General relativity acts weirdest of all at the center of massive objects, a location called a singularity, where the equations developed by Schwarzschild to explain the nature of gravity simply blow up to infinity and aren’t useful at all. But that’s fine, too, because it’s just a math bug. It’s not like anything in nature could actually get that small, right?

 

What if an object could be compressed so much, reaching such ridiculous densities, that its Schwarzschild radius were on the outside, instead of safely buried in the center, away from where its mathematics could cause any trouble? Well that would be weird, because then there would be no other physical effects to swamp out the oddity of gravity at this boundary.

Indeed, gravity would be so strong at this boundary that nothing, not even light, could escape. And any matter that fell in would spiral helplessly to its doom in the infinitely dense singularity. 

If such an object existed, then the singularity and the Schwarzschild radius would be promoted from mathematical cruft to physical object.

Spoiler alert: It’s a black hole.

For decades, it was assumed that something, anything, would prevent stars from forming black holes. But after the discoveries of white dwarf stars and neutron stars — both immensely dense — and the first hints of the triggering mechanism for supernovas, black holes began to take hold as a concept.

As much as they ought not to exist, if they did exist, they would have certain real, observable, testable properties. So at least science can do its thing, discard this crazy notion and move on with its life.

And oh boy, did the evidence start to come in. A massive dying star, orbiting an unseen companion that pulls on its atmosphere so much it emits powerful X-rays. Stars in the center of the Milky Way orbiting a massive, hidden object. Powerful radio sources emanating from active galaxies, with energies only reached through immense gravity coupled to fantastic rotation. And most recently, the subtle whisper of gravitational waves sloshing over the Earth.

The inescapable conclusion: Black holes are real.

A singular problem

We’ve come to terms with the event horizon, the name now given to an exposed Schwarzschild radius. The nature of space-time inside that boundary does indeed get all sorts of funky, but hey — nature does lots of funky things, so after a few decades of mulling it over, scientists decided it wasn’t so bad. 

But the singularity remains — the point of infinite density at the center of every black hole. That word — infinite — is a hard pill to swallow. When infinites appear in the mathematics, it’s a signpost that we’re doing something wrong, that our machinery isn’t quite up to the task. We’re missing something.

No matter what, we can’t point to any other force or effect or pressure to stop the catastrophic collapse of matter into a singularity — and we’ve really, really tried. Hard.

But we know our theoretical models (i.e., general relativity) are incomplete. There isn’t really a singularity at the center of a black hole. But we simply don’t understand strong gravity at small scales. That’s the domain of a full-on quantum theory of gravity, which we haven’t cracked despite decades of trying. Hard.

So the question of whether black holes exist comes down to your definition of the word “exist.” Black holes as astrophysical objects? Yeah, it looks like nature can manufacture event horizons just fine. Black holes as a 100 percent complete picture of the way nature works? Those certainly don’t exist, and will eventually be replaced by a more accurate picture. Someday.

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Cassini Captures On Saturn’s Rings

September 19, 2017 by  
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NASA’s Cassini spacecraft has captured a spectacular photo of a perplexing wave structure in one of Saturn’s rings as the probe heads into its final days at the gas giant. 

The rings of Saturn are embedded with billions of water-ice particles ranging in size from grains of sand to monstrous chunks. Saturn’s rings also feature waves that propagate outward in spiral patterns. 

The new image from Cassini captures an up-close view of a spiral density wave visible in Saturn’s B ring. The wave structure is a buildup of material that has formed from the gravitational pull of Saturn’s moons, NASA officials said.

The density wave visible in Saturn’s B ring originates 59,796 miles (96,233 kilometers) from the planet, where the “ring particles orbit Saturn twice for every time the moon Janus orbits

In the new image, the wave structure — aptly named the Janus 2:1 spiral density wave — appears to ricochet outward, away from Saturn and toward the upper-left corner of the photo, creating hundreds of bright wave crests. 

The density wave is generated by the gravitational pull of Saturn’s moon Janus. However, Janus and one of Saturn’s other moons, Epimetheus, share practically the same orbit and swap places every four years, creating a new crest in the wave, according to the statement. 

As a result, the distance between any pair of crests corresponds to four years’ worth of wave oscillations. This pattern represents the orbital history of Janus and Epimetheus, much like the rings of a tree reveal information about its growth. 

Based on this idea, the crests of the wave at the very upper left of the new Cassini image correspond to the positions of Janus and Epimetheus during the Saturn flybys of NASA’s twin Voyager probes in 1980 and 1981, according to the statement.

The recent images of Saturn’s B ring were taken on June 4, 2017, using Cassini’s narrow-angle camera. After 20 historic years in space, the Cassini mission will come to a close on Sept. 15, when the spacecraft will intentionally dive into Saturn’s atmosphere. 

 

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Can The James Webb Telescope Find Life In Our Solar System

September 18, 2017 by  
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The soon-to-launch James Webb Space Telescope will turn its powerful eye on two of the solar system’s top candidates for hosting alien life: the icy moons Enceladus and Europa, the agency confirmed in a statement this month.

Both Europa (a moon of Jupiter) and Enceladus (a moon of Saturn) are thought to possess subsurface oceans of liquid water beneath thick outer layers of ice. Both moons have also shown evidence of enormous plumes of liquid shooting up through cracks in the surface ice; these plumes could be caused by subsurface geysers, which could provide a source of heat and nutrients to life-forms there, scientists have said.

“We chose these two moons because of their potential to exhibit chemical signatures of astrobiological interest,” said Heidi Hammel, executive vice president of the Association of Universities for Research in Astronomy (AURA), who is leading an effort to use the telescope to study objects in Earth’s solar system.  

The James Webb Space Telescope, nicknamed “Webb,” will capture infrared light, which can be used to identify objects that generate heat but are not hot enough to radiate light (including humans, which is why many night-vision systems utilize infrared light). Researchers are hoping that Webb can help to identify regions on the surfaces of these moons where geologic activity, such as plume eruptions, are taking place. 

Enceladus’ plumes were studied in detail by the Cassini probe at Saturn. The spacecraft spotted hundreds of plumes, and even flew through some of them and sampled their composition. Europa’s plumes were spotted by the Hubble Space Telescope, and researchers know far less about them than those on Europa.

“Are they made of water ice? Is hot water vapor being released? What is the temperature of the active regions and the emitted water?” Geronimo Villanueva, lead scientist on the Webbobservation of Europa and Enceladus, said in the statement. “Webb telescope’s measurements will allow us to address these questions with unprecedented accuracy and precision.”

Webb’s observations will help pave the way for the Europa Clipper mission, a $2 billion orbital mission to the icy moon. Scheduled to launch in the 2020s, Europa Clipper will search for signs of life on Europa. The observations with Webb could identify areas of interest for the Europa Clipper mission to investigate, according to the statement.

As seen by Webb, the Saturn moon Enceladus will appear about 10 times smaller than Europa, so scientists will not be able to capture high-resolution views of Enceladus’ surface, according to the statement. However, Webb can still analyze the molecular composition of Enceladus’ plumes. 

But it’s also possible that the observations won’t catch a plume erupting from Europa’s surface; scientists don’t know how frequently these geysers erupt, and the limited observing time with Webb may not coincide with one of them. The telescope can detect organics — elements such as carbon that are essential to the formation of life as we know it — in the plumes. However, Villanueva cautioned that Webb does not have the power to directly detect life-forms in the plumes.

Webb is set to launch in 2018 and will orbit the sun at the L2 Lagrange point, which is about one million miles (1.7 million km) farther from the sun than the Earth’s orbit around the sun. The telescope will provide high-resolution views of both the very distant and very nearby universe. Scientists have already begun submitting ideas for objects or regions that should be observed using Webb’s powerful eye, and Europa and Enceladus are among the objects that are now guaranteed observing time.

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Project Blue Telescope Goes CrowdFunding

September 15, 2017 by  
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The private space telescope initiative Project Blue launched a new crowdfunding campaign Sept. 6 in a second attempt to raise money for its mission to directly image Earth-like exoplanets. 

The initiative aims to launch a small space telescope into low-Earth orbit. The telescope will spy on our interstellar neighbor Alpha Centauri and image any Earth-like planets that might orbit the star system.

In support of Project Blue, BoldlyGo Institute and numerous organizations, including the SETI (Search for Extraterrestrial Intelligence) Institute, the University of Massachusetts Lowell and Mission Centaur, launched an IndieGoGo campaign to raise $175,000 over the next two months. The funds will be used to establish mission requirements, design the initial system architecture and test its capability for detecting exoplanets. Project leaders will also begin looking for potential partners who could manufacture parts of the space telescope, representatives said in a statement. 

“We’re very excited to pursue such an impactful space mission and, as a privately-funded effort, to include a global community of explorers and space science advocates in Project Blue from the beginning,” Jon Morse, CEO of BoldlyGo Institute, said in the statement.

Last year, Project Blue organizers attempted to raise $1 million through the crowdfunding platform Kickstarter, but the campaign was canceled after only $335,597 was contributed and Project Blue received none of the funds (as is Kickstarter’s policy). 

With the IndieGoGo campaign, however, the organizers have a more flexible goal and will be able to keep all contributions from supporters, even if the initial goal of $175,000 is not reached. So far, more than $45,000 has been raised through the campaign.

The neighboring star system Alpha Centauri is located only 4.37 light-years from Earth, making it a target for scientific research. Project Blue estimates it will take about $50 million to build the special-purpose telescope, which is planned to launch in 2021. 

The small space telescope will use a specialized coronagraph to block the bright glare of Alpha Centauri’s stars and detect planets that may be orbiting there. One planet, Proxima b, has already been detected around Proxima Centauri. 

However, Proxima b was discovered indirectly, by measuring the planet’s gravitational effect on its host star. Instead, the Project Blue telescope will be designed to directly image Earth-like planets in Alpha Centauri’s neighborhood.

 

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