Dec. 20, 2013
Copyright ESA / DLR / FU Berlin (G. Neukum)
The innermost moon of Mars, Phobos, is seen here in full 360 degree glory. The images were taken by the High Resolution Stereo Camera (HRSC) on ESA’s Mars Express at various times throughout the mission’s 10 years.
The moon’s parallel sets of grooves are perhaps the most striking feature, along with the giant 9 km-wide Stickney impact crater that dominates one face of the 27 x 22 x 18 km moon.
The origin of the moon’s grooves is a subject of much debate. One idea assumes that the crater chains are associated with impact events on the moon itself.
Another idea suggests they result from Phobos moving through streams of debris thrown up from impacts 6000 km away on the surface of Mars, with each ‘family’ of grooves corresponding to a different impact event.
Mars Express has imaged Phobos from a wide range of distances, but will make its closest flyby yet on 29 December 2013, at just 45 km above the moon.
Although this is too close to take images, gravity experiments will give insight into the interior structure of Phobos.
Maintaining a record of solar measurements is important in understanding the sun’s effect on Earth and the National Oceanic and Atmospheric Administration’s (NOAA), Total solar irradiance Calibration Transfer Experiment, or TCTE, is now providing that information.
Many natural conditions on Earth such as the surface temperature or air temperature depend on energy that comes from the sun in the form of electromagnetic radiation. A solar cycle lasts about 11 years and typically has modest changes in solar radiation. There are also dramatic solar events that eject solar material, but the energy variation caused by these particle emissions, when averaged over a year or longer, is small compared to variations in the sun’s electromagnetic radiation.
Scientists have noted these changes in the sun’s energy by observing from Earth’s surface for more than a hundred years, but were only able to begin to determine their magnitude and impact on Earth’s climate with more accurate measurements from space, starting in 1978 with measurements of the “total solar irradiance,” or TSI, made by NASA’s Nimbus 7 satellite.
Data from NASA’s Chandra X-ray Observatory has revealed faint remnants of a supernova explosion and helped researchers determine Circinus X-1 — an X-ray binary — is the youngest of this class of astronomical objects found to date.
As the name suggests, X-ray binaries are star systems made up of two parts: a compact stellar remnant — either a neutron star or a black hole; and a companion star — a normal star like our sun. As they orbit one another, the neutron star or black hole pulls in gas from the companion star. This heats the gas to millions of degrees, producing intense X-ray radiation and making these star systems some of the brightest X-ray sources in the sky.
Sebastian Heinz and his team at the University of Wisconsin-Madison (UW) discovered Circinus X-1 is less than 4,600 years old, making it the youngest X-ray binary system ever seen. This discovery, made in parallel with a radio telescope in Australia, provides scientists unique insight into the formation of neutron stars and supernovas, and the effect of the supernova’s explosion on a nearby companion star.
“X-ray binaries provide us with opportunities to study matter under extreme conditions that would be impossible to recreate in a laboratory,” Heinz said. “For the first time, we can study a newly minted neutron star in an X-ray binary system.”
Astronomers have detected hundreds of X-ray binaries throughout the Milky Way and other nearby galaxies. However, these older X-ray binaries, with ages typically measured in millions of years, only reveal information about what happens much later in the evolution of these systems.
“It’s critical that we see what these X-ray binaries are doing at all stages of their lives,” said co-author Paul Sell, also of UW. “Circinus X-1 is showing us what happens in a cosmic blink of an eye after one of these objects is born.”
To determine the age of Circinus X-1, the team of astronomers needed to examine the material around the orbiting pair of stars. However, the overwhelming brightness of the neutron star made it too difficult for researchers to observe that interstellar gas. The team recently caught a break, when they observed the neutron star in a very faint state — dim enough for scientists to detect the X-rays from the supernova shock wave that plowed through the surrounding interstellar gas.
“Since the supernova was triggered by the formation of the neutron star, our limit on the age of the supernova remnant also limits the age of the neutron star in Circinus X-1,” said co-author Robert Fender of the University of Oxford in the U.K.
The youth of Circinus X-1 helps explain its wild swings in brightness and the highly unusual orbit of its two stars, which had puzzled astronomers for years. The orbit is very eccentric — non-circular — and the period during which the two stars orbit each other is decreasing by several minutes every year. This is exactly what is expected for a young X-ray binary disrupted by a supernova explosion before the gravitational pull of the stars on each other has had time to circularize and stabilize the orbit.
Previous observations with other telescopes indicated the magnetic field of the neutron star in Circinus X-1 is weak. That, in addition to the star system’s young age, has led to two possible theories: either a neutron star can be born with a weak magnetic field, or it can quickly become de-magnetized as it pulls material from its companion star onto itself. Neither conclusion was expected from existing theories of neutron star evolution.
In our galaxy, the only other established X-ray binary within a supernova remnant is SS 433, which is between 10,000 and 100,000 years old, and behaves in many ways like an older version of Circinus X-1. Two other candidate X-ray binaries in nearby galaxies have ages similar to SS 433.
In addition to the Chandra data, radio observations from the Australia Telescope Compact Array were critical in these findings. A paper describing these results is available online and appears in the Dec. 4 issue of The Astrophysical Journal.
NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Mass., controls Chandra’s science and flight operations.
Chandra X-ray Center, Cambridge, Mass.
Marshall Space Flight Center, Huntsville, Ala.
A new study using observations from a novel instrument provides the best look to date at magnetic fields at the heart of gamma-ray bursts, the most energetic explosions in the universe. An international team of astronomers from Britain, Slovenia and Italy has glimpsed the infrastructure of a burst’s high-speed jet.
Gamma-ray bursts are the most luminous explosions in the cosmos. Most are thought to be triggered when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole. The black hole then drives jets of particles that drill all the way through the collapsing star and erupt into space at nearly the speed of light.
On March 8, 2012, NASA’s Swift satellite detected a 100-second pulse of gamma rays from a source in the constellation Ursa Minor. The spacecraft immediately forwarded the location of the gamma-ray burst, dubbed GRB 120308A, to observatories around the globe.
The world’s largest fully autonomous robotic optical telescope, the 2-meter Liverpool Telescope located at Roque de los Muchachos Observatory on La Palma in the Canary Islands, automatically responded to Swift’s notification.
“Just four minutes after it received Swift’s trigger, the telescope found the burst’s visible afterglow and began making thousands of measurements,” said lead researcher Carole Mundell, who heads the gamma-ray burst team at the Astrophysics Research Institute at Liverpool John Moores University in the U.K.
The telescope was fitted with an instrument named RINGO2, which Mundell’s team designed to detect any preferred direction, called polarization, in the vibration of light waves from burst afterglows.
Mundell’s team built RINGO2 in order to probe the magnetic fields long postulated to drive and focus the jets of gamma-ray bursts. The shoe-box-sized instrument pairs a spinning polarizing filter with a super-fast camera.
Energy across the spectrum, from radio waves to gamma rays, is emitted when a jet slams into its surroundings and begins to decelerate. This results in the formation of an outward-moving shock wave. At the same time, a reverse shock wave drives back into the jet debris, also producing bright emission.
“One way to picture these different shocks is by imagining a traffic jam,” Mundell said. “Cars approaching the jam abruptly slow down, which is similar to what happens in the forward shock. Cars behind them slow in turn, resulting in a wave of brake lights that moves backward along the highway, much like the reverse shock.”
Theoretical models of gamma-ray bursts predict that light from the reverse shock should show strong and stable polarized emissions if the jet possesses a structured magnetic field originating from the environment around the newly-formed black hole, thought to be the “central engine” driving the burst.
Previous observations of optical afterglows detected polarizations of about 10 percent, but they provided no information about how this value changed with time. As a result, they could not be used to test competing jet models.
The Liverpool Telescope’s rapid targeting enabled the team to catch the explosion just four minutes after the initial outburst. Over the following 10 minutes, RINGO2 collected 5,600 photographs of the burst afterglow while the properties of the magnetic field were still encoded in its captured light.
The observations show that the initial afterglow light was polarized by 28 percent, the highest value ever recorded for a burst, and slowly declined to 16 percent, while the angle of the polarized light remained the same. This supports the presence of a large-scale organized magnetic field linked to the black hole, rather than a tangled magnetic field produced by instabilities within the jet itself.
A paper describing the team’s findings will appear in the Dec. 5 issue of the journal Nature.
“This is a remarkable discovery that could not have occurred without the lickety-split response times of the Swift satellite and the Liverpool Telescope,” said Neil Gehrels, the Swift principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Md.
› Download additional graphics from NASA Goddard’s Scientific Visualization Studio
› Paper: “Highly polarized light from stable ordered magnetic fields in GRB 120308A”
› “NASA Sees ‘Watershed’ Cosmic Blast in Unique Detail” (Nov. 21, 2013)
› “NASA’s Fermi, Swift See ‘Shockingly Bright’ Burst” (05.03.13)
› “NASA’s Fermi Telescope Sees Most Extreme Gamma-ray Blast Yet” (02.19.09)
› “‘Naked-Eye’ Gamma-Ray Burst Was Aimed Squarely At Earth” (09.10.08)
NASA’s Goddard Space Flight Center, Greenbelt, Md.
The ALHAMBRA project, led by researchers from the Instituto de Astrofísica de Andalucía and in which the University of Valencia has participated, has identified and classified more than half a million galaxies, after seven years of close observation of the universe from the Observatory of Calar Alto (CAHA, Almería) and thanks to a technique that breaks the stars energy in their colors through astronomical filters.
In addition, this research has also allowed calculating the distances from these galaxies to us with unprecedented accuracy. ALHAMBRA (Advanced Large, Homogeneous Area Medium Band Redshift Astronomical survey) has a system of twenty filters covering all wavelengths in the optical and three filters in the infrared, which allows to accurately determine the energy emitted by galaxies and the distance of half a million galaxies with unprecedented depth for the sample size.
The ALHAMBRA mapping represents an ambitious scientific project that has mobilized scientists from sixteen research institutes. Led by Mariano Moles (CEFCA) and developed in the Instituto de Astrofísica de Andalucía (IAA-CSIC), it was tailored designed to trace the universe evolution during the last ten million years. “ALHAMBRA represents a decisive step to board pressing issues in cosmology and astrophysics through photometric mapping, that allow getting the accuracy required to the distance of the detected objects,” Moles says. Thus, “the unbiased character of these mappings allows obtaining relevant data for all cosmic scales and, in this sense, the ALHAMBRA project is a precursor of the new long-range mapping that is being proposed,” the researcher adds.
Continue Learning: http://www.redorbit.com/news/space/1113017069/alhambra-publishes-most-detailed-catalogue-galaxies-120213/
Comet ISON May Have Survived
Nov. 29, 2013
Continuing a history of surprising behavior, material from Comet ISON appeared on the other side of the sun on the evening on Nov. 28, 2013, despite not having been seen in observations during its closest approach to the sun.
As ISON appeared to dim and fizzle in several observatories and later could not be seen at all by NASA’s Solar Dynamics Observatory or by ground based solar observatories, many scientists believed it had disintegrated completely. However, a streak of bright material streaming away from the sun appeared in the European Space Agency and NASA’s Solar and Heliospheric Observatory later in the evening. The question remains whether it is merely debris from the comet, or if some portion of the comet’s nucleus survived, but late-night analysis from scientists with NASA’s Comet ISON Observing Campaign suggest that there is at least a small nucleus intact.
Throughout the year that researchers have watched Comet ISON – and especially during its final approach to the sun – the comet brightened and dimmed in unexpected ways. Such brightness changes usually occur in response to material boiling off the comet, and different material will do so at different temperatures thus providing clues as to what the comet is made of. Analyzing this pattern will help scientists understand the composition of ISON, which contains material assembled during the very formation of the solar system some 4.5 billion years ago.
For more information on Comet ISON: www.nasa.gov/ison
To download recent ISON imagery: http://svs.gsfc.nasa.gov/Gallery/CometISON.html
NASA’s solar observing fleet to watch Comet ISON’s journey around the Sun
Posted Nov. 22, 2013 by Karen C. Fox
It began in the Oort cloud, almost a light year away. It has traveled for over a million years. It has almost reached the star that has pulled it steadily forward for so long. On Thanksgiving Day, Nov. 28, 2013, Comet ISON will finally sling shot around the sun. Here its inward journey through the solar system will end—either because it will break up due to intense heat and gravity of the sun, or because, still intact, it speeds back away, never to return.
Catalogued as C/2012 S1, Comet ISON was first spotted 585 million miles away in September 2012. Scientists were instantly intrigued, not because spotting it so far away meant it might be very bright and beautiful once it was closer to Earth—though this may indeed turn out to be the case if it survives its trip around the sun—but because this is ISON’s very first trip into the inner solar system. That means it is still made of pristine matter from the earliest days of the solar system’s formation, its top layers never having been lost by a trip near the sun. Along Comet ISON’s journey, NASA has used a vast fleet of spacecraft and Earth-based telescopes to learn more about this time capsule from when the solar system first formed.
Continue Learning: http://phys.org/news/2013-11-nasa-solar-fleet-comet-ison.html
Powerful Gamma-Ray Burst Detected Close To Milky Way
November 21, 2013
Lee Rannals for redOrbit.com – Your Universe Online
Astronomers from around the world have compiled data from satellites and observatories to help explain the most powerful gamma-ray burst ever recorded, according to a study published in the journal Science.
Led by researchers from the Niels Bohr Institute and the University of Leicester, the international team said this gamma-ray burst occurred relatively close to the Milky Way. Gamma-ray bursts (GRBs) are violent bursts of gamma radiation typically associated with an exploding massive star.
When a star explodes as a supernova it releases the gamma-ray bursts, which are so bright that they can be seen from across the universe. Telescopes underneath Earth’s atmosphere are unable to detect this light, however; so astronomers rely on space-based observatories such as the Swift satellite to pick up on them.
Swift monitors the skies and typically discovers about 100 gamma-ray bursts each year, but the one they found this past April was particularly unusual.
Infant Galaxies Merge Near ‘Cosmic Dawn’
November 21, 2013
Astronomers using the combined power of the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile and NASA’s Hubble and Spitzer space telescopes have discovered a far-flung trio of primitive galaxies nestled inside an enormous blob of primordial gas nearly 13 billion light-years from Earth. It’s possible the trio will eventually merge into a single galaxy similar to our own Milky Way.
“This exceedingly rare triple system, seen when the universe was only 800 million years old, provides important insights into the earliest stages of galaxy formation during a period known as ‘cosmic dawn,’ when the universe was first bathed in starlight,” said Richard Ellis of the California Institute of Technology, Pasadena, a member of the research team.
Researchers first detected this object, which appeared to be a giant bubble of hot, ionized gas, in 2009. Dubbed Himiko (after a legendary queen of ancient Japan), it is nearly 10 times larger than typical galaxies of that era and comparable in size to our own Milky Way. Subsequent infrared observations with NASA’s Spitzer Space Telescope provided more clues about the object’s mass, suggesting Himiko might represent a single galaxy, which would make it uncharacteristically massive for that period of the early universe.
Continue Learning: http://www.jpl.nasa.gov/news/news.php?release=2013-338
Exploring the dark universe at the speed of petaflops
Nov 21, 2013 by Gail Pieper
An astonishing 95% of our universe is made of up dark energy and dark matter. Understanding the physics of this sector is the foremost challenge in cosmology today. Sophisticated simulations of the evolution of the universe play a crucial role.
The primary lens through which scientists look at the night sky is no longer only a telescope—it’s also a supercomputer. The new and coming generations of supercomputers will finally be capable of modeling the universe in the detail and volume required by astronomical surveys of the sky that are now underway, or soon will be.
Scientists use large cosmological simulations to test theories about the structure of the universe and the evolution of the distribution of galaxies and clusters of galaxies. State-of-the-art supercomputers let cosmologists make predictions and test them against data from powerful telescopes and space probes. Two decades of surveying the sky have culminated in the celebrated Cosmological Standard Model. Yet two of the model’s key pillars—dark matter and dark energy, together accounting for 95% of the universe—remain mysterious. A research team led by Argonne is tackling this mystery, aided by some of the world’s fastest supercomputers.
Continue Learning: http://phys.org/news/2013-11-exploring-dark-universe-petaflops.html
NASA sees ‘watershed’ cosmic blast in unique detail
Posted: Nov 21, 2013 by Francis Reddy
(Phys.org) —On April 27, a blast of light from a dying star in a distant galaxy became the focus of astronomers around the world. The explosion, known as a gamma-ray burst and designated GRB 130427A, tops the charts as one of the brightest ever seen
A trio of NASA satellites, working in concert with ground-based robotic telescopes, captured never-before-seen details that challenge current theoretical understandings of how gamma-ray bursts work.
“We expect to see an event like this only once or twice a century, so we’re fortunate it happened when we had the appropriate collection of sensitive space telescopes with complementary capabilities available to see it,” said Paul Hertz, director of NASA’s Astrophysics Division in Washington.
Gamma-ray bursts are the most luminous explosions in the cosmos, thought to be triggered when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole. The black hole then drives jets of particles that drill all the way through the collapsing star and erupt into space at nearly the speed of light.
Gamma-rays are the most energetic form of light. Hot matter surrounding a new black hole and internal shock waves produced by collisions within the jet are thought to emit gamma-rays with energies in the million-electron-volt (MeV) range, or roughly 500,000 times the energy of visible light. The most energetic emission, with billion-electron-volt (GeV) gamma rays, is thought to arise when the jet slams into its surroundings, forming an external shock wave.
The Gamma-ray Burst Monitor (GBM) aboard NASA’s Fermi Gamma-ray Space Telescope captured the initial wave of gamma rays from GRB 130427A shortly after 3:47 a.m. EDT April 27. In its first three seconds alone, the “monster burst” proved brighter than almost any burst previously observed.
Continue Learning: http://phys.org/news/2013-11-nasa-watershed-cosmic-blast-unique.html
Dark Matter Reveals the Structure of the Universe
by BIG THINK EDITORS NOVEMBER 20, 2013, 12:00
Physics is both deeply inspiring and deeply humbling, in a way that few other disciplines are today. On the one hand, physicists have found the elusive Higgs boson, the particle responsible for mass. On the other hand, physicists are comparatively clueless when it comes to dark matter, which makes up the vast majority of the Universe.
Comparatively clueless, that is to say, but not completely clueless.
In the video below, Joel Primack, an astrophysicist at the University of California-Santa Cruz, explains that we don’t yet know the real nature of the dark matter “beyond that it’s pretty cold.” Cold refers to the terminology that Primack coined in 1983. Dark matter is either hot, warm or cold “depending on how rapidly it’s moving in the early stages of the Big Bang,” Primack says.
Continue Learning: http://bigthink.com/big-think-tv/dark-matter-reveals-the-structure-of-the-universe?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+bigthink%2Fmain+(Big+Think+Main)
NASA sees late season subtropical storm Melissa form in Atlantic
Nov 19, 2013 by Rob Gutro
Hurricane Season ends on November 30, and subtropical storm Melissa formed with less than two weeks to go. Melissa formed on Monday, November 18 about 695 miles/1,120 km east-southeast of Bermuda, near 29.3 north and 53.6 west. It had maximum sustained winds near 50 mph/85 kph and was moving to the northwest at 9 mph/15 kph.
NASA’s TRMM satellite flew above subtropical storm Melissa as it formed in the central Atlantic Ocean on November 18, 2013 at 1449 UTC (9:49 a.m. EST). TRMM captured rainfall data on Melissa using TRMM’s Microwave Imager (TMI) and Precipitation Radar (PR). Both data were overlaid on an enhanced visible/infrared image from TRMM’s Visible and InfraRed Scanner (VIRS). The TRMM pass found that the heaviest rainfall within Melissa was falling at a rate of over 74mm~2.9 inches per hour in an area of strong convective rainfall that was wrapping around the southern side of the storm.
Continue Learning: http://phys.org/news/2013-11-nasa-late-season-subtropical-storm.html
Update to Comet ISON
November 19, 2013; 12:40 PM
Recently, we have seen some changes in the brightness of Comet ISON.
Notice how the magnitude (a measure of the brightness) has gone from around 10 at the end of October to near 4 now. For the everyday person, that means that ISON has become around 200 times brighter in a matter of weeks and has been visible to the naked eye in many locations. Magnitude 6 is the general threshold for visibility to the naked eye. The smaller the magnitude number, the brighter an object is. For example, the Full Moon has a magnitude of about -12, and Venus, a bright “star,” is around -4.
So, what happened to make it so much brighter? Some scientists hypothesized that ISON has started to break up, or small fragments have broken away and that this may have caused an increase in its brightness. However, there is no hard evidence to prove or disprove that. The more likely reason is that ISON has had a series of “outbursts,” in which gases and water are expelled from the comet, which causes the brightness to go up (the magnitude down). This reason is supported by the European Southern Observatory’s TRAPPIST telescope.
To understand further what is going on now and what will happen with ISON, let’s take a look at its orbit around the sun.
Continue Learning: http://www.accuweather.com/en/weather-blogs/astronomy/update-to-comet-ison-1/20109318
Martian Geology More Diverse Than Previously Thought
November 18, 2013
Brett Smith for redOrbit.com – Your Universe Online
For years, scientists have thought of Mars as being made up of just one kind of rock – a very simplistic planet compared to the diverse geology of Earth.
However, a new study in the journal Nature Geoscience suggests there may be granite on Mars and puts forward a theory for how it could have formed there.
“We’re providing the most compelling evidence to date that Mars has granitic rocks,” said study author James Wray, an assistant professor of earth and atmospheric sciences at the Georgia Institute of Technology.
The study is based on the large deposit of feldspar, a mineral found in granite, recently found in an inactive Martian volcano. The location of the feldspar suggests protracted magmatic activity under the Martian surface could produce large-scale granite deposits, the study team said.
The Martian surface is mostly covered with basalt, the dark-colored rock commonly found throughout Hawaii. However, in the area around the Martian feldspar deposit, minerals rich in iron and magnesium and common in basalts are almost completely absent.
Continue Learning: http://www.redorbit.com/news/space/1113006200/mars-has-granite-111813/
Astrophysicists tackle the Sun and one of physics’ biggest unsolved problems
Nov 18, 2013 by Beth Kwon
Daniel Wolf Savin and Michael Hahn have been fascinated by the universe since they were boys. For Savin, a senior research scientist in the Columbia Astrophysics Laboratory, discovering Albert Einstein at age 12 spurred the desire to “learn everything about the universe.” Years later, Hahn, an associate research scientist who grew up 40 miles from Savin’s home town in Connecticut, started gazing at the stars as a teenager; he eventually became president of the astronomy club at his alma mater, Carnegie Mellon.
Now the two have made a big leap toward cracking one of the biggest mysteries in astrophysics—why the corona, or plasma surrounding the sun, is so much hotter than the sun’s surface.
The coronal heating problem, as it is known, is important because the corona is the source of solar wind, which is responsible for the northern and southern lights and can also disrupt telecommunications and power grids. “Satellites can be slowly pushed out of their orbits if they’re deflected by the solar wind so if we can better understand the cause, we can create better models for space weather,” says Savin, referring to conditions beyond the atmosphere.
Continue Learning: http://phys.org/news/2013-11-astrophysicists-tackle-sun-physics-biggest.html
November 18, 2013
To the Cassini spacecraft’s infrared eyes, Saturn’s graceful clouds sometimes take on the appearance of an impressionist’s painting of the giant planet.
This view looks toward the sunlit side of the rings from about 18 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on Aug. 12, 2013 using a spectral filter sensitive to wavelengths of near-infrared light centered at 728 nanometers.
The view was acquired at a distance of approximately 994,000 miles (1.6 million kilometers) from Saturn. Image scale is 57 miles (92 kilometers) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.
To learn more about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov or http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org.
Credit: NASA/JPL-Caltech/Space Science Institute
New Algorithm Will Help Curiosity Rover Analyze Mars Soil
November 16, 2013
While the instruments on NASA’s Mars rover Curiosity are able to easily identify the chemical composition of rocks, measure the speed of the wind and snap amazing images from mast-mounted cameras, the process of analyzing soil images can be a somewhat daunting task, according to researchers from Louisiana State University (LSU).
After all, the university points out, many times there are several thousand images to analyze, and the soil particles are typically only five to 10 pixels wide. Now, however, a research team led by Suniti Karunatillake of the LSU Department of Geology and Geophysics has come to the rescue with a new algorithm that should make the task easier.
Karunatillake and colleagues from Rider University, Stony Brook University and the US Geological Survey (USGS) in Flagstaff, Arizona joined forces to create an image analysis and segmentation algorithm specifically to help NASA scientists complete this basic, but nonetheless challenging, part of their mission.
Continue Learning: http://www.redorbit.com/news/space/1113005274/mars-curiosity-algorithm-for-soil-images-111613/
Strange Object Boosts Kuiper Belt Mystery
NOV 13, 2013 01:48 PM ET // BY IAN O’NEILL
There’s something odd floating around in the outer solar system. Actually, there’s lots of odd things floating around in the outer solar system, but 2002 UX25 is one of the most baffling.
The mid-sized Kuiper belt object (KBO) measures 650 kilometers (400 miles) across, and yet it has a density less than water (less than 1 gram per cubic centimeter). Yes, if you put it in a huge bathtub, 2002 UX25 would float.
As we probably all know by now, the Kuiper belt — a populated region of the solar system found just beyond the orbit of Neptune — is a strange place. Once thought to have a population of just one, astronomers have identified thousands of other minor planetary bodies. In fact, it was the accelerated discoveries in the Kuiper belt that ultimately led to the reclassification (or demotion, depending on which way you look at it) of Pluto from “planet” to lowly “dwarf planet.”
Dynamics of Ice, Water and Salts in the Martian Subsurface
October 22 2013
Recent discoveries on Mars suggest ice may be or recently was present at latitudes where it is not expected and at unexplained abundance. As ice may be unstable under present Martian climatic conditions, a mechanism may be needed to explain the presence of ice in the near surface at these latitudes. Water release history, chemical composition, and heat fluxes are variable over the surface of Mars, and there could be more than one mechanism responsible for near-surface ice. The purpose of this numerical modeling study is to show that thermochemical circulation of brines in the subsurface of Mars is a possible mechanism that can deposit ice and brine, close to, or even at, the surface of Mars.
JUL 30, 2013 12:03 PM ET // BY RAY VILLARD
Hurtling toward the Pluto system at 33,000 mph, NASA’s New Horizons probe was briefly awakened from electronic hibernation earlier this month to go through a full dress rehearsal for the July 2015 flyby.
With eight cameras and four spectrometers running on an anemic 30 watts of power, New Horizons is “the most sophisticated payload ever sent on a first reconnaissance mission,” said principal investigator Alan Stern of the Southwest Research Institute during a presentation at the Johns Hopkins Applied Physics Laboratory in Laurel, Md., on July 23.
Stern emphasizes that this is a mission of superlatives. New Horizons is the fastest manmade object ever built. It is not only reaching the farthest classical planet in the solar system, but also surveying a new class of binary world.
There is little doubt that Pluto could have fascinating weather and geology, and serve as a Rosetta stone for the history of the solar system’s vast outer rim. This region, called the Kupier belt, contains countless icy bodies — perhaps 900 others the size of Pluto.
The marathon flight will complete our initial reconnaissance of the solar system that began over 50 years ago at the dawn of the Space Age. There will never be another time like this in the history of mankind.
Yes, we’ve sent orbiters and landers to follow in the track of the trailblazing probes like Voyager and Pioneer. But to people under age 30 today, the Pluto mission will be their first — and maybe last — experience at the thrill of seeing a new world close-up for the first time. The last planetary flyby was of Neptune in the summer of 1989 by Voyager 2.
Published on May 19, 2013
After 10 years and more than 3 billion miles, the New Horizons spacecraft is now halfway between Earth and Pluto, on approach for a dramatic flight past the icy planet and its moons in July 2015.
Published on May 3, 2013
View full lesson: http://ed.ted.com/lessons/dark-matter…
The Greeks had a simple and elegant formula for the universe: just earth, fire, wind, and water. Turns out there’s more to it than that — a lot more. Visible matter (and that goes beyond the four Greek elements) comprises only 4% of the universe. CERN scientist James Gillies tells us what accounts for the remaining 96% (dark matter and dark energy) and how we might go about detecting it.
Lesson by James Gillies, animation by TED-Ed.
(Watch More Videos)
Kuiper Belt Was a ‘War Zone’ — A Detective Story
MAR 16, 2013 08:11 PM ET // BY IAN O’NEILL
Astronomy can be a cosmic detective story, and our enduring fascination with the solar system’s mysterious hinterland of small icy objects in the Kuiper belt is no exception.
In fact, as wonderfully detailed by Mike Brown, professor of planetary astronomy at the California Institute of Technology (Caltech), his detective work focuses on the growing population of dwarf planet discoveries in the Kuiper belt, revealing the frigid region used to be a pretty violent place.
Brown took a retrospective look at his research during the W. M. Keck Observatory 20th Anniversary Science Meeting at The Fairmont Orchid, Hawaii, the Big Island, on Thursday. Brown is famously known as the “Pluto Killer” — he discovered the dwarf planet Eris in 2005 that, ultimately, led to Pluto being reclassified by the International Astronomical Union (IAU) in 2006. The fascinating story is revealed in his best-selling book, “How I Killed Pluto and Why It Had It Coming.”
Although each Kuiper belt object its own unique story of discovery, Brown discussed the detection and investigation of the oddball dwarf planet (136108) Haumea — a world approximately a third of the mass of Pluto. Originally discovered by Brown’s Caltech team using the Palomar Observatory in 2004, key observations were carried out with the Keck Observatory telescopes atop Mauna Kea, Hawaii. “We named the object Haumea in honor of the work done at Keck,” said Brown. In Hawaiian mythology, Haumea is the goddess of fertility and childbirth.
When the 21st century began, scientists studying Earth’s climate thought the gigantic ice caps on Greenland and Antarctica would melt slowly around the edges and lag behind the overall global warming of climate.
But this past decade, the warmest on record, proved the climate modelers wrong.
Glaciers have been melting much faster than ever expected and researchers have been trying to understand why.
The uptick in melting ice has not been restricted to the Arctic and Antarctic. Europe’s glaciers are now thought to be entering their final decades.
The famous snows of Kilimanjaro and other low-latitude mountains could disappear completely. The thick, perennial sea ice of the Arctic is fast disappearing, which will likely bring ice-free summers to the Arctic Ocean.
There are global consequences to this melting. Rising seas will make more cities and islands vulnerable to catastrophic flooding like that which nearly killed New Orleans. Mountain glaciers around the world bring fresh water to billions. Any way you slice it, an Earth with less ice is a less hospitable planet.
NASA IMAGE COURTESY THE NASA/GSFC/METI/ERSDAC
Discover more images: http://news.discovery.com/history/archaeology/discoveries-of-the-decade.htm
Astronaut Mike Hopkins tweeted this picture from the International Space Station.
Upsala Glacier Retreat
This photograph by an astronaut on the International Space Station highlights the snout of the Upsala Glacier (49.88°S, 73.3°W) on the Argentine side of the North Patagonian Icefield. Ice flow in this glacier comes from the north (right in this rotated image). Dark lines of rocky debris (moraine) within the ice give a sense of the slow ice flow from right to left.
Published on Nov 29, 2012
It was one of the greatest mysteries in modern science: a series of brief but extremely bright flashes of ultra-high energy light coming from somewhere out in space. These gamma ray bursts were first spotted by spy satellites in the 1960s. It took three decades and a revolution in high-energy astronomy for scientists to figure out what they were.
Far out in space, in the center of a seething cosmic maelstrom. Extreme heat. High velocities. Atoms tear, and space literally buckles. Photons fly out across the universe, energized to the limits found in nature. Billions of years later, they enter the detectors of spacecraft stationed above our atmosphere. Our ability to record them is part of a new age of high-energy astronomy, and a new age of insights into nature at its most extreme. What can we learn by witnessing the violent birth of a black hole?
The outer limits of a black hole, call the event horizon, is subject to what Albert Einstein called frame dragging, in which space and time are pulled along on a path that leads into the black hole. As gas, dust, stars or planets fall into the hole, they form into a disk that spirals in with the flow of space time, reaching the speed of light just as it hits the event horizon. The spinning motion of this so-called “accretion disk” can channel some of the inflowing matter out into a pair of high-energy beams, or jets.
How a jet can form was shown in a supercomputer simulation of a short gamma ray burst. It was based on a 40-millisecond long burst recorded by Swift on May 9, 2005. It took five minutes for the afterglow to fade, but that was enough for astronomers to capture crucial details. It had come from a giant galaxy 2.6 billion light years away, filled with old stars.
Scientists suspected that this was a case of two dead stars falling into a catastrophic embrace. Orbiting each other, they moved ever closer, gradually gaining speed. At the end of the line, they began tearing each other apart, until they finally merged. NASA scientists simulated the final 35 thousandths of a second, when a black hole forms.
Chaos reigns. But the new structure becomes steadily more organized, and a magnetic field takes on the character of a jet. Within less than a second after the black hole is born, it launches a jet of particles to a speed approaching light.
A similar chain of events, in the death of a large star, is responsible for longer gamma ray bursts. Stars resist gravity by generating photons that push outward on their enormous mass. But the weight of a large star’s core increases from the accumulation of heavy elements produced in nuclear fusion. In time, its outer layers cannot resist the inward pull… and the star collapses. The crash produces a shock wave that races through the star and obliterates it.
In the largest of these dying stars, known as collapsars or hypernovae, a black hole forms in the collapse. Matter flowing in forms a disk. Charged particles create magnetic fields that twist off this disk, sending a portion out in high-speed jets.
Simulations show that the jet is powerful enough to plow its way through the star. In so doing, it may help trigger the explosion. The birth of a black hole does not simply light up the universe. It is a crucial event in the spread of heavy elements that seed the birth of new solar systems and planets.
But the black hole birth cries that we can now register with a fleet of high-energy telescopes are part of wider response to gravity’s convulsive power.
(Watch More Videos)
Published on Aug 8, 2012
Planetary exploration is a historic endeavor and a major focus of NASA. New Horizons is designed to help us understand worlds at the edge of our solar system by making the first reconnaissance of Pluto and Charon – a “double planet” and the last planet in our solar system to be visited by spacecraft. Then, as part of an extended mission, New Horizons would visit one or more objects in the Kuiper Belt region beyond Neptune.
Uploaded on Jan 3, 2009
To some there is no vision more reassuring: the cycles of the sun and the moon, the heavens ceaselessly turning. The night sky is unchanging and eternal — Or so it seems. But modern astronomy has given us a much different vision: a universe that roils and vents its rage… In fierce radiation jets that erupt from newborn stars. In netherworlds where matter billions of times the mass of our sun collapses to a single point. In the most violent explosions since the Big Bang… The supernova.
Uploaded on Jan 3, 2009
In the fold of our home galaxy, the Eagle Nebula is one of the richest of the great star nurseries. Intense stellar winds have sculpted a majestic castle of gas. Inside these giant columns, stars are being born. Yet for the dying stars that set this process in motion, the consequences are grim. Supernovae leave in their wake a range of bizarre objects. Among them, tiny ultra-dense objects called neutron stars, and their strange, other worldly cousins, black holes.
Uploaded on Jul 11, 2008