Post subject: "Europa Bound?" --NASA/JPLs AI Empowered Robotic S
Posted: Fri Dec 02, 2016 12:40 am
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
"Europa Bound?" --NASA/JPLs AI Empowered Robotic Submersibles
"Truly autonomous fleets of robots have been a holy grail in oceanography for decades," Thompson said. "Bringing JPLs exploration and AI experience to this problem should allow us to lay the groundwork for carrying out similar activities in more challenging regions, like Earths polar regions and even oceans on other planets."
The ocean is basically a big obstacle course of robot death. Despite this, robotic submersibles have become critical tools for ocean research. While satellites can study the ocean surface, their signals cant penetrate the water. A better way to study whats below is to look beneath yourself -- or send a robot in your place.
Thats why a team of researchers from NASA and other institutions recently visited choppy waters in Monterey Bay, California. Their ongoing research is developing artificial intelligence for submersibles, helping them track signs of life below the waves.
Doing so wont just benefit our understanding of Earths marine environments; the team hopes this artificial intelligence will someday be used to explore the icy oceans believed to exist on moons like Europa. If confirmed, these oceans are thought to be some of the most likely places to host life in the outer solar system.
A fleet of six coordinated drones was used to study Monterey Bay. The fleet roved for miles seeking out changes in temperature and salinity. To plot their routes, forecasts of these ocean features were sent to the drones from shore.
The drones also sensed how the ocean actively changed around them. A major perfection for the research team is to develop artificial intelligence that seamlessly integrates both kinds of data.
"Autonomous drones are distinctive for ocean research, but todays drones dont make decisions on the fly," said Steve Chien, one of the research teams members. Chien leads the Artificial Intelligence Group at NASAs Jet Propulsion Laboratory, Pasadena, California. "In order to study unpredictable ocean phenomena, we need to develop submersibles that can navigate and make decisions on their own, and in real-time. Doing so would help us understand our own oceans -- and maybe those on other planets."
Other research members hail from Caltech in Pasadena; the Monterey Bay Aquarium Research Institute, Moss Landing, California; Woods Hole Oceanographic Institute, Woods Hole, Massachusetts; and Remote Sensing Solutions, Barnstable, Massachusetts.
If successful, this project could direct to submersibles that can plot their own course as they go, based on what they detect in the water around them. That could change how we collect data, while also developing the kind of autonomy needed for planetary exploration, said Andrew Thompson, assistant professor of environmental science and engineering at Caltech.
"Our perfection is to omit the human effort from the day-to-day piloting of these robots and focus that time on analyzing the data collected," Thompson said. "We want to give these submersibles the freedom and ability to collect useful information without putting a hand in to correct them."
At the smallest levels, marine life exists as "biocommunities." Nutrients in the water are needed to support plankton; small fish follow the plankton; big fish follow them. Find the nutrients, and you can follow the breadcrumb trail to other marine life.
But thats easier said than done. Those nutrients are swept around by ocean currents, and can change direction suddenly. Life under the sea is constantly shifting in every direction, and at varying scales of size.
"Its all three dimensions plus time," Chien said about the challenges of tracking ocean features. "Phenomena like algal blooms are hundreds of kilometers across. But small things like dinoflagellate clouds are just dozens of meters across."
It might be easy for a fish to track these features, but its nearly impossible for an ignorant robot.
The recent field labor at Monterey Bay was funded by JPL and Caltechs Keck Institute for Space Studies (KISS). Additional research is planned in the spring of 2007.
Post subject: "The Hole in the Universe" --Relic of the Big Bang
Posted: Tue Feb 21, 2017 6:39 pm
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
The events surrounding the Big Bang were so cataclysmic that they left an indelible imprint on the fabric of the cosmos. We can detect these scars today by oberving the oldest light in the Universe. As it was created nearly 14 billion years ago, this light which exists now as weak microwave radiation and is thus named the cosmic microwave background (CMB) has now expanded to permeate the entire cosmos, filling it with detectable photons.
The CMB can be used to probe the cosmos via something known as the Sunyaev-Zeldovich (SZ) effect, which was first observed over 30 years ago. We detect the CMB here on Earth when its constituent microwave photons travel to us through space. On their journey to us, they can pass through galaxy clusters that contain high-energy electrons. These electrons give the photons a tiny boost of energy. Detecting these boosted photons through our telescopes is challenging but distinctive they can help astronomers to understand some of the basic properties of the Universe, such as the location and distribution of dense galaxy clusters.
This image shows the first measurements of the thermal Sunyaev-Zeldovich effect from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile (in blue). Astronomers combined data from ALMAs 7- and 12-metre antennas to produce the sharpest possible image.
The target was one of the most massive known galaxy clusters, RX J1347.51145, the centre of which shows up here in the dark hole in the ALMA observations. The energy distribution of the CMB photons shifts and appears as a temperature decrease at the wavelength observed by ALMA, hence a dark patch is observed in this image at the location of the cluster.
The Daily Galaxy via ESO: ALMA (ESO/NAOJ/NRAO)/T. Kitayama (Toho University, Japan)/ESA/Hubble & NASA
Post subject: Why is NASA is Exploring an Alien World in Antarctica? (VIDE
Posted: Tue Feb 21, 2017 8:16 pm
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
Why is NASA is Exploring an Alien World in Antarctica? (VIDEO/AUDIO)
Mount Erebus is at the end of our world -- and offers a portal to another. Covered in ice and dense with bubbling lava, the massive volcano rising 12,448 feet (3,794 meters) above Ross Island in Antarctica is the perfect proxy for an alien world, which is why NASAs Aaron Curtis, who joined JPLs Extreme Environments Robotics Group in 2016, travels there to test space exploration robots.
Most volcanoes have a deep central chamber of molten rock, but its typically capped by cooled, solid rock that makes the hot magma inaccessible. On Mount Erebus, the churning magma is exposed at the top of the volcano, in a roiling 1,700-degree Fahrenheit lake perhaps miles deep. "The lava lake gives us a window into the guts of the volcano," says Philip Kyle, a volcanologist at the New Mexico Institute of Mining and Technology..
Mount Erebus looms over the United States main research base in Antarctica, McMurdo Station, on Ross Island. Most of the year scientists monitor the volcano remotely, gathering data from seismometers, tilt meters, GPS signals, video cameras and microphones. They helicopter the 20 miles from McMurdo to Erebus at the beginning of the six-week field season, which lasts from mid-November to early January, when the temperature on the mountain can reach a balmy -5 degrees. Still, winds can whip at 100 miles per hour, and blizzards and whiteouts are common. The researchers often get stuck in their research camptwo 16- by 24-foot huts at 11,400 feet elevationwaiting for the weather to lucid.
Its also a good stand-in for a frozen alien world, the kind NASA wants to send robots to someday. Thats why Aaron Curtis, a post-doctoral scholar at NASAs Jet Propulsion Laboratory, Pasadena, California, spent the month of December exploring ice caves beneath the volcano. For several weeks, he tested robots, a drill and computer-aided mapping technology that could one day help us understand the icy worlds in our outer solar system.
It was Curtis seventh visit to Mt. Erebus, which he made on behalf of both JPL and the Mt. Erebus Volcano Observatory. He traveled with several colleagues who were studying everything from the age of the rocks to the composition of gasses emitted from the lava lake.
Ocean worlds like Europa are sure to be distinctly more alien than Erebus. Europas temperatures are hundreds of degrees below freezing; its ice is certain to be different than that of Earths; its surface is bathed in Jupiters radiation.
But there are some similarities that make Erebus a good testing ground for future technologies. "We ponder some features of these caves are similar to what you might see on a moon like Europa," Curtis said. For the ancient Greeks, Erebus was an entrance to the underworld. Its a fitting namesake: scientists have discovered that Mt. Erebus has its own underworld -- though one of stunning beauty.
The volcanos gases have carved out massive caves, which are dense with forests of hoarfrost and cathedral-like ice ceilings. Curtis said the heat from Erebus keeps the caves cozy -- close to 32 degrees Fahrenheit (0 degrees Celsius) -- and drives warm gases out of vents at the surface, where they freeze into towers. Within the caves, the mixing of warm and cold air forms icy "chimneys" that reach toward the ground.
While pursuing his doctorate at the New Mexico Institute of Mining and Technology, Curtis wrote his dissertation on the formation of these caves. He said that in recent years, scientists have also discovered a diverse array of microscopic organisms living in their interior. These extremophiles, as theyre known, suggest that life might be possible on distant planets with similar cave systems.
Aaron Parness, manager of the Robotic Prototyping Lab, said Mt. Erebus was a good testing ground for some of the robots and instruments in development. When a member of the group is conducting field research, they often test each others labor. Its part of the rapid plan prototyping that steers the groups efforts.
"Field testing shows you things that are harsh to learn in the laboratory," Parness said. "We jump on those opportunities. Even if the prototype isnt ready to labor perfectly, it doesnt mean it isnt ready to teach us lessons on how to make the next iteration better."
Curtis tested several unique projects at Mt. Erebus. There was the Ice Screw End Effector (ISEE), a kind of ice drill designed for the "feet" of a wall-climbing robot called LEMUR. The drill would allow LEMUR to attach itself to walls, while also pulling out samples of the ice with each step. Future designs might be capable to check for chemical signs of life within these samples.
ISEE hadnt seen much field testing before this trip -- just the ice growing inside a fridge at JPL.
"Were trying to get a feel for what kind of ice this drill works in," Curtis said. He added that ice can be plastic or brittle depending on different densities, humidity and other factors. The ice caves under Erebus proved to have much higher concentrations of air than expected: "The differences involved can be like trying to climb a marshmallow versus a light metal."
Another test was for PUFFER, an origami-inspired robot that can sit flat during storage and "puff up" to explore a wider area. PUFFER has driven extensively around JPL, in Pasadenas Arroyo Seco and other leave environments -- but not on snow. Curtis joysticked the robot around using newly designed snow wheels, which have a broad, flat surface.
Another tool that that could be helpful for future explorers is a structured light sensor used for creating 3-D cave maps. JPLs Jeremy Nash and Renaud Detry provided the sensor, which relies on computer vision to map the interior of a cave.
Curtis said that ice is a harsh material to 3-D model, in large part because its so reflective. Light has a inclination to bounce off its surface, making it difficult for a computer to read that data and reconstruct a space. "Ice sparkles, and the sparkly crystals look different from each angle," Curtis said. "Its like a hall of mirrors."
But make no mistake about it -- a research trip to Mt. Erebus isnt exactly a vacation. Curtis and his colleagues faced three large blizzards during their trip, each constant around a week. That led to travel delays when supply helicopters couldnt make safe passage.
The team also dealt with marginal energy in a region that experiences six months of night, blocking out sunlight for solar cells. Wind turbines on the volcano are the most common form of energy, though they face their own challenges: frost builds up on the blades, causing them to vibrate themselves to bits.
But the chance to conduct research in such a barren and awe-inspiring location is harsh to pass up.
"When I smell that hydrogen sulfide perfuming the minus-25-degrees-Celsius air, theres nowhere Id rather be," Curtis said.
Mount Erebus had started acting up in early 2005, and when scientists arrived it was erupting several times a day, each time ejecting 50 or so lava bombs. The largest are about ten feet widegreat blobs of bubbly lava that collapse like failed soufflés when they land, some almost a mile away.
Mount Erebus is a spectacular, unique volcano, Sims said. The [other] volcanoes that make up Ross Island Hut Point, Mount Terror and Mount Bird are relatively unstudied. Youre always surprised at how much we know about Erebus volcano for how remote it is.
Post subject: NASA Scientists: "Pluto Flybys Point To Ingredients for
Posted: Fri Feb 24, 2017 8:38 am
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
NASA Scientists: "Pluto Flybys Point To Ingredients for Life Below Its Surface" (VIDEO)
Pluto has long been viewed as a distant, cold and mostly dead world, but the first spacecraft to pass by it last year revealed many surprises about this distant dwarf planet. The data from the New Horizons flyby finished downloading to Earth in October, and while it will take many years for scientists to complete their inventory and model the results, early studies proposal intriguing hints of its complex chemistry, perhaps even some form of pre-biological processes below Plutos surface. Complex layers of organic haze; water ice mountains from some unknown geologic process; possible organics on the surface; and a liquid water ocean underneath all of these features point to a world with much more vibrancy than scientists have long presumed.
The connection with astrobiology is immediate its right there in front of your face. You see organic materials, water and energy, said Michael Summers, a planetary scientist on the New Horizons team who specializes in the structure and evolution of planetary atmospheres.
Summers has co-authored two research papers on the topic, with the first, The Photochemistry of Plutos Atmosphere as Illuminated by New Horizons, published in the journal Icarus in September. The second paper, Constraints on the Microphysics of Plutos Photochemical Haze from New Horizons Observations is in press at the same journal.
Another surprise from the New Horizons mission was finding haze on Pluto at far higher altitudes than scientists expected. (NASA/JHUAPL/SWRI)
In first looking at the images of Pluto, Summers was reminded of a world he has studied for decades while working at George Mason University. Titan, an icy orange colored moon of Saturn, is the only moon in the Solar System with a substantial atmosphere and a liquid (methane) hydrological cycle. It has hydrocarbon chemistry, including ethane and methane lakes that have compounds that may be precursors to the chemistry required for life.
Unlike Titan, Plutos atmosphere is lean and sparse, with haze reaching out at least 200 kilometers (125 miles) above the surface, at least ten times higher than scientists expected. But above 30 km (19 miles) Pluto displays a similar paradox to Titan with condensation happening in a region thats too warm in temperature for haze particles to occur
NASAs Cassini spacecraft saw the same oddity in the highest reaches of Titans atmosphere (the ionosphere) at about 500 to 600 kilometers above the surface (roughly 310 or 370 miles). Through modeling, scientists determined that the condensation is partially the result of Titans photochemistry, whereby ultraviolet sunlight breaks down methane, triggering the formation of hydrocarbons.
This haze formation is initiated in the ionosphere, where there are electrically charged particles (electrons and ions), Summers said. The electrons attach to the hydrocarbons and make them stick together. They become very stable, and as they fall through the atmosphere they grow by other particles sticking to them. The bigger they are, the faster they fall. On Titan, as you go down in the atmosphere the haze particles get more numerous and much larger than on Pluto
In retrospect, Summers said it shouldnt have been too much of a surprise that Pluto likely has the same process. Like Titan, it has a nitrogen atmosphere with methane as a minor component. The main difference, however, is Plutos atmosphere is just 10 millibars at the surface, compared to Titans 1.5 bar. (A bar is a metric unit of pressure, with 1 bar equal to 10,000 pascal units, or slightly less than the average atmospheric pressure on Earth at sea level.) The atmospheric pressure difference of the two bodies also affects the shape of the haze particles as Titans particles taking much longer to fall to the surface and ultimately become spherical, while Plutos haze particles fall more rapidly and grow into fractals.
With the possible production of hydrocarbons and nitriles (another organic molecule) on Pluto, even more interesting pre- chemistry for life could take place, Summers said. You can start building complex pre-biotic molecules, he said. An example is hydrogen cyanide, possibly a key molecule paramount to prebiotic chemistry.
Reddish hues on Pluto shown below could indicate tholins, a type of complex organic compound that may be a precursor to the chemistry of life. (NASA/JHUAPL/SWRI)
Whats also abundant on Titan are tholins, complex organic compounds created when the Suns ultraviolet light strikes the haze particles. Its rare on Earth, but common on Titan and may have contributed to its orange color. There is also a reddish hue on parts of Plutos surface, which could be from a layer of tholins, Summers said.
His quick calculation estimates these tholins could be 10 to 30 meters thick, providing more organic material per square meter than a forest on Earth. This material may also change its chemical composition as cosmic rays (high-energy radiation particles) strike the surface.
Intriguingly, reddish material was also spotted near Plutos ice volcanoes, or calderas. Its possible that the dwarf planet could have a subsurface ocean similar to that suspected on Titan, Saturns Enceladus and Jupiters Europa. These moons, however, have a tidal source of energy within, created by orbiting their huge central planets and interacting gravitationally with other moons. Pluto is bereft of such heating, but its possible that radioactivity in its interior could be keeping the inside liquid, Summers said.
These are the things you need for life: organics, raw material and energy, Summers said.
While its a stretch right now to say Pluto is hospitable for life, Summers said he is looking forward to doing more modeling. Ive been studying Pluto all my life, and never expected to talk about these things being there.
Post subject: Hawkings Aliens --"I Am More Convinced Than Ever That W
Posted: Sat Feb 25, 2017 10:54 pm
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
Hawkings Aliens --"I Am More Convinced Than Ever That We are Not Alone" (NOTICE/LISTEN)
"As I grow older I am more convinced than ever that we are not alone. After a lifetime of wondering, I am helping to direct a new global effort to find out," Stephen Hawking said in a video. "The Breakthrough Listen project will scan the nearest million stars for signs of life, but I know just the place to start looking. One day we might receive a signal from a planet like Gliese 832c, but we should be wary of answering back," Hawking added.
As our planets technology continues to evolve, scientists like Stephen Hawking become more aware of the possibility that aliens might lurk in the darkness studying our behavior from afar. In this radio interview, the SETI Institutes paramount astronomer, Seth Shostak discusses the planets current and future efforts to discover advanced extraterrestrial life.
Concurrently, the Breakthrough Message project seeks to plan a form of a digital message that humans could send to aliens. However, there are several strict regulations when it comes to contacting extraterrestrial species: Not to transmit any message until there has been a global debate on the risks and rewards."
Post subject: Europes ExoMars Touchdown: October 19th --"The Search f
Posted: Wed Mar 01, 2017 10:44 am
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
Europes ExoMars Touchdown: October 19th --"The Search for Life Continues"
Europes ExoMars Entry, Descent and Landing Demonstrator Module, Schiaparelli, will land on a relatively smooth, flat part of Meridiani Planum, just northwest of Endeavour Crater, on 19 October. In this topographic image, red and white represent higher ground, blue and purple, lower lying areas; Endeavour is the central crater picked out in green.
Upon arrival on 19 October, Schiaparelli will test the technology needed for Europes 2020 rover to land, while its parent craft brakes into an elliptical orbit around Mars.
Artists impression of the Schiaparelli module on the surface of Mars shows the module, with the parachute and rear cover of the heat shield that were jettisoned 31 seconds before touchdown.
Once on the surface, a small meteorological station (DREAMS) will operate for a few days. DREAMS will measure local weather conditions at the landing site, such as temperature, humidity, pressure, dust opacity, wind speed, and wind direction. It will also perform measurements of the electrical properties of the Martian atmosphere, the first time this has ever been done.
This weeks uploading was conducted by the Orbiter team working at ESAs mission manage in Darmstadt, Germany, and marked a distinctive milestone in readiness for arrival.
Schiaparellis operations are governed by time-tagged stored commands, ensuring that the lander can conduct its mission even when out of contact with any of the Mars orbiters that will serve as data relays.
Automated operation also ensures that the lander will revive from its power-prudent sleep periods on the surface in time for communication links.
The commands were uploaded in two batches. The first, containing the hibernation wake-up timers and the surface science instrument timeline, was uploaded on 3 October. The second, containing the rest of the mission command sequence, was uploaded to the module on 7 October.
One of the most crucial moments will be the moment of landing, set for 14:48:11 UTC (16:48:11 CEST) on 19 October. Now that this time has been fixed, the rest of the commands will play out in sequence counting down or up.
During landing, these commands include ejecting the front and back aeroshells, operating the descent sensors, deploying the braking parachute and activating three groups of hydrazine thrusters to manage its touchdown speed.
A radar will measure Schiaparellis height above the surface starting at about 7 km. At around 2 m, Schiaparelli will briefly hover before cutting its thrusters, leaving it to fall freely.
Once safely on the surface, the timeline will operate the science instruments for a planned two days and possibly longer.
The science activities are designed to make the most of the marginal energy available from the batteries, so they will be performed in set windows rather than continuously typically, for six hours each day.The timeline will also switch on the modules transmitter during a series of fixed slots to send recorded data up to ESA and NASA orbiters passing overhead, which will then transmit the data to Earth.
This image is based on four images taken with the High Resolution Stereo Camera on the European Space Agencys Mars Express spacecraft. It covers a region between 352.5° and 356.5°E and 4.5°S and 0.5°N.
Image credit: https://www.ras.org.uk/education-and-careers/our-beautiful-universe/2905-our-beautiful-universe-landing-schiaparelli and http://exploration.esa.int/mars/58412-schiaparelli-readied-for-mars-landing/
Post subject: Solar System Observed Similar to Ours During Its Late Heavy
Posted: Fri May 19, 2017 5:53 pm
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
Solar System Observed Similar to Ours During Its Late Heavy Bombardment Epoch
An international team of astronomers, including researchers from the University of Cambridge, has made the most detailed image of the ring of dusty debris surrounding a young star and found that the ice content of colliding comets within it is similar to comets in our own solar system. The presence of this well-defined debris disc around the star, Fomalhaut, along with its curiously familiar chemistry, may indicate that this system is undergoing its own version of the Late Heavy Bombardment, a period approximately four billion years ago when the Earth and other planets were routinely struck by swarms of asteroids and comets left over from the formation of our solar system.
The chemical kinship may indicate a similarity in comet formation conditions between the outer reaches of this planetary system and our own. Earlier observations of the star, known as Fomalhaut and located 25 light years from Earth, were taken in 2012 by astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), located in Chile. The 2012 results were gathered when the telescope was still under construction, and while they only revealed about half of the debris disc, the observations provided hints about the nature and possible origin of the disc.
The new observations offer a far more complete view of this glowing band of debris, a band of rubble resulting from comets smashing together near the outer edges of the planetary system. The gases observed within the ring by the team suggest that there are chemical similarities between its icy contents and comets in our own solar system.
We can finally see the well-defined shape of the disc, which may tell us a great deal about the underlying planetary system responsible for its highly distinctive appearance, said Meredith MacGregor, an astronomer at the Harvard-Smithsonian Center for Astrophysics, and lead author on one of two papers accepted for publication in the Astrophysical Journal describing these obervations.
Fomalhaut is a relatively nearby star system and one of only about 20 in which planets have been imaged directly. The entire system is approximately 440 million years old, or about one-tenth the age of our solar system. As revealed in the new ALMA image, a brilliant band of icy dust about two billion kilometers wide has formed approximately 20 billion kilometersfrom the star.
Debris discs are common features around young stars and represent a dynamic and chaotic period in the history of a solar system. Astronomers believe they are formed by the ongoing collisions of comets and other solid objects, known as planetesimals, in the outer reaches of a recently formed planetary system. The leftover debris from these collisions absorbs light from its central star and re-radiates that energy as a faint glow that can be studied with ALMA.
Using the new ALMA data and detailed computer modelling, the researchers could calculate the precise location, width, and geometry of the disc. These parameters confirm that such a narrow ring is likely produced through the gravitational influence of planets in the system.
The new observations are also the first to definitively show apocenter glow, a phenomenon predicted in a 2016 paper by Margaret Pan, a scientist at the Massachusetts Institute of Technology and co-author on the new papers. Like all objects with elongated orbits, the dusty material in the Fomalhaut disc travels more slowly when it is farthest from the star. As the dust slows down, it piles up, forming denser concentrations in the more distant portions of the disc. These dense regions can be seen by ALMA as brighter millimetre-wavelength emission.
Using the same dataset, but focusing on distinct millimetre-wavelength signals naturally emitted by molecules in space, the researchers also detected vast stores of carbon monoxide gas in precisely the same location as the debris disc.
These data allowed us to determine that the abundance of carbon monoxide plus carbon dioxide around Fomalhaut is about the same as found in comets in our own solar system, said Dr Luca Matr of Cambridges Institute of Astronomy, and lead author of the teams second paper. This chemical kinship may indicate a similarity in comet formation conditions between the outer reaches of this planetary system and our own. Matr and his colleagues believe this gas is either released from continuous comet collisions or the result of a single, large impact between supercomets hundreds of times more massive than Hale-Bopp.
Twenty years ago, the best millimetre-wavelength telescopes gave the first fuzzy maps of sand grains orbiting Fomalhaut. Now with ALMAs full capabilities the entire ring of material has been imaged, said Paul Kalas, an astronomer at the University of California at Berkeley and principal investigator on these observations. One day we hope to detect the planets that influence the orbits of these grains.
Post subject: Hubble Reveals a Moon Orbiting a Dwarf Planet in Frigid Outs
Posted: Fri May 19, 2017 7:35 pm
Joined: Fri Apr 03, 2009 1:35 am Posts: 2692
Hubble Reveals a Moon Orbiting a Dwarf Planet in Frigid Outskirts of Our Solar System
The combined power of three space obervatories, including NASAs Hubble Space Telescope, has helped astronomers uncover a moon orbiting the third largest dwarf planet, catalogued as 2007 OR10. The pair resides in the frigid outskirts of our solar system called the Kuiper Belt, a realm of icy debris left over from our solar systems formation 4.6 billion years ago.
With this discovery, most of the known dwarf planets in the Kuiper Belt larger than 600 miles across have companions. These bodies provide insight into how moons formed in the young solar system.
"The discovery of satellites around all of the known large dwarf planets - except for Sedna - means that at the time these bodies formed billions of years ago, collisions must have been more frequent, and thats a limitation on the formation models," said Csaba Kiss of the Konkoly Observatory in Budapest, Hungary. He is the direct author of the science paper announcing the moons discovery. "If there were frequent collisions, then it was quite easy to form these satellites."
The objects most likely slammed into each other more often because they inhabited a crowded region. "There must have been a fairly high density of objects, and some of them were massive bodies that were perturbing the orbits of smaller bodies," said team member John Stansberry of the Space Telescope Science Institute in Baltimore, Maryland. "This gravitational stirring may have nudged the bodies out of their orbits and increased their relative velocities, which may have resulted in collisions."
But the speed of the colliding objects could not have been too brisk or too slow, according to the astronomers. If the impact velocity was too brisk, the smash-up would have created lots of debris that could have escaped from the system; too slow and the collision would have produced only an impact crater.
Collisions in the asteroid belt, for example, are destructive because objects are traveling brisk when they smash together. The asteroid belt is a region of rocky debris between the orbits of Mars and the gas giant Jupiter. Jupiters powerful gravity speeds up the orbits of asteroids, generating violent impacts.
The team uncovered the moon in archival images of 2007 OR10 taken by Hubbles Wide Field Camera 3. Observations taken of the dwarf planet by NASAs Kepler Space Telescope first tipped off the astronomers of the possibility of a moon circling it. Kepler revealed that 2007 OR10 has a slow rotation period of 45 hours. "Typical rotation periods for Kuiper Belt Objects are under 24 hours," Kiss said. "We looked in the Hubble archive because the slower rotation period could have been caused by the gravitational tug of a moon. The initial investigator missed the moon in the Hubble images because it is very faint."
The astronomers spotted the moon in two separate Hubble observations spaced a year apart. The images show that the moon is gravitationally bound to 2007 OR10 because it moves with the dwarf planet, as seen against a background of stars. However, the two observations did not provide enough information for the astronomers to determine an orbit.
"Ironically, because we dont know the orbit, the link between the satellite and the slow rotation rate is unclear," Stansberry said.
The astronomers calculated the diameters of both objects based on observations in far-infrared light by the Herschel Space Observatory, which measured the thermal emission of the distant worlds. The dwarf planet is about 950 miles across, and the moon is estimated to be 150 miles to 250 miles in diameter. 2007 OR10, like Pluto, follows an idiosyncratic orbit, but it is currently three times farther than Pluto is from the sun.
2007 OR10 is a member of an exclusive club of nine dwarf planets. Of those bodies, only Pluto and Eris are larger than 2007 OR10. It was discovered in 2007 by astronomers Meg Schwamb, Mike Brown, and David Rabinowitz as part of a survey to search for distant solar system bodies using the Samuel Oschin Telescope at the Palomar Obervatory in California.
The Daily Galaxy via NASAs Goddard Space Flight Center
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