NASA Investigating the Life of Comet ISON

After several days of continued observations, scientists continue to work to determine and to understand the fate of Comet ISON: There's no doubt that the comet shrank in size considerably as it rounded the sun and there's no doubt that something made it out on the other side to shoot back into space. The question remains as to whether the bright spot seen moving away from the sun was simply debris, or whether a small nucleus of the original ball of ice was still there. Regardless, it is likely that it is now only dust.  

Comet ISON, which began its journey from the Oort Cloud some 3 million years ago, made its closest approach to the sun on Nov. 28, 2013. The comet was visible in instruments on NASA's Solar Terrestrial Relations Observatory, or STEREO, and the joint European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, via images called coronagraphs. Coronagraphs block out the sun and a considerable distance around it, in order to better observe the dim structures in the sun's atmosphere, the corona. As such, there was a period of several hours when the comet was obscured in these images, blocked from view along with the sun. During this period of time, NASA's Solar Dynamics Observatory could not see the comet, leading many scientists to surmise that the comet had disintegrated completely. However, something did reappear in SOHO and STEREO coronagraphs some time later – though it was significantly less bright.

Whether that spot of light was merely a cloud of dust that once was a comet, or if it still had a nucleus – a small ball of its original, icy material – intact, is still unclear. It seems likely that as of Dec. 1, there was no nucleus left. By monitoring its changes in brightness over time, scientists can estimate whether there's a nucleus or not, but our best chance at knowing for sure will be if the Hubble Space Telescope makes observations later in December 2013.

Regardless of its fate, Comet ISON did not disappoint researchers. Over the last year, observatories around the world and in space gathered one of the largest sets of comet observations of all time, which should provide fodder for study for years to come. The number of space-based, ground-based, and amateur observations were unprecedented, with twelve NASA space-based assets observing over the past year.

Related Links:

For more information on Comet ISON: www.nasa.gov/ison

To download recent ISON imagery: http://svs.gsfc.nasa.gov/Gallery/CometISON.html

NASA and Planetary Resources Sign Agreement to Crowdsource Asteroid Detection

NASA and Planetary Resources Inc., of Bellevue, Wash., are partnering to develop crowd-sourced software solutions to enhance detection of near-Earth objects using agency-funded data. The agreement is NASA's first partnership associated with the agency's Asteroid Grand Challenge.

Under a non-reimbursable Space Act Agreement, Planetary Resources will facilitate the use of NASA-funded sky survey data and help support the algorithm competition and review results. NASA will develop and manage the contests and explore use of the best solutions for enhancing existing survey programs. The first contest is expected to launch early in 2014 based on Planetary Resources' and Zooniverse's Asteroid Zoo platform currently in development. The partnership was announced Nov. 21 at NASA's Asteroid Initiative Ideas Synthesis Workshop in Houston.

"This partnership uses NASA resources in innovative ways and takes advantage of public expertise to improve identification of potential threats to our planet," said Lindley Johnson, program executive of NASA's near Earth object observation program. "This opportunity is one of many efforts we're undertaking as part of our asteroid initiative."

Through NASA's asteroid initiative, the agency is enhancing its ongoing efforts to identify and characterize near-Earth objects for scientific investigation, find asteroids potentially hazardous to Earth and find candidates viable for redirection to a stable orbit near the moon as a destination for exploration by astronauts.

"The foundation of the asteroid grand challenge is partnerships like this one," said Jason Kessler, program executive for the asteroid grand challenge. "It fits the core purpose of the grand challenge perfectly: find innovative ways to combine ideas and resources to solve the problem of dealing with potentially hazardous asteroids."

NASA's efforts capitalizes on activities across the agency's human exploration, science and space technology efforts

"Asteroids hold the resources necessary to enable a sustainable, even indefinite presence in space -- for science, commerce and continued prosperity here on Earth," said Chris Lewicki, president and chief engineer of Planetary Resources. "By harnessing the public's interest in space and asteroid detection, we can more quickly identify the potential threats, as well as the opportunities."

The algorithm contests are managed and executed by NASA's Center of Excellence for Collaborative Innovation (CoECI). CoECI was established at the request of the White House Office of Science and Technology Policy to advance NASA open innovation efforts and extend that expertise to other federal agencies. CoECI uses NASA Tournament Lab (NTL) for its advanced algorithmic and software development contests.  Through its contract with Harvard Business School in association with Harvard's Institute of Quantitative Social Sciences, NTL uses the TopCoder platform to enable a community of over 600,000 competitors to create the most innovative, efficient and optimized solutions for specific, real-world challenges faced by NASA.

Source: www.nasa.gov

NASA Sees 'Watershed' Cosmic Blast in Unique Detail

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.

Source: www.nasa.gov

MAVEN Prelaunch Updates

MAVEN Launch Preps on Schedule

Fri, 18 Nov 2013 10:40 AM EDT

MAVEN launch preparations remain on schedule and have continued to go well since spacecraft processing resumed earlier this month. On Tuesday, Oct. 22, MAVEN is slated for a spin test without propellant aboard. Once complete, the spacecraft will be prepared for fueling. The Atlas V rocket payload fairing will be moved into the clean room on Oct. 21 in preparation for MAVEN's encapsulation beginning in early November.

The Atlas booster was hoisted into the vertical integration facility at Cape Canaveral Air Force Station's Space Launch Complex 41 on Oct. 11, and the Centaur upper stage was hoisted atop the Atlas the following Monday. United Launch Alliance has completed powering of the stacked vehicle for checkout. The Combined Systems Test, an electrical test of the rocket, is scheduled for Oct. 22.

The launch of MAVEN is scheduled for Nov. 18 at 1:28 p.m. EST.

Source: http://www.nasa.gov/

Asteroid 2013 TV135 – A Reality Check

Newly discovered asteroid 2013 TV135 made a close approach to Earth on Sept. 16, when it came within about 4.2 million miles (6.7 million kilometers). The asteroid is initially estimated to be about 1,300 feet (400 meters) in size and its orbit carries it as far out as about three quarters of the distance to Jupiter's orbit and as close to the sun as Earth's orbit. It was discovered on Oct. 8, 2013, by astronomers working at the Crimean Astrophysical Observatory in Ukraine. As of Oct. 14, asteroid 2013 TV135 is one of 10,332 near-Earth objects that have been discovered.

With only a week of observations for an orbital period that spans almost four years, its future orbital path is still quite uncertain, but this asteroid could be back in Earth’s neighborhood in 2032. However, NASA’s Near-Earth Object Program Office states the probability this asteroid could then impact Earth is only one in 63,000. The object should be easily observable in the coming months and once additional observations are provided to the Minor Planet Center in Cambridge, Mass., the initial orbit calculations will be improved and the most likely result will be a dramatic reduction, or complete elimination, of any risk of Earth impact.  

"To put it another way, that puts the current probability of no impact in 2032 at about 99.998 percent," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. "This is a relatively new discovery. With more observations, I fully expect we will be able to significantly reduce, or rule out entirely, any impact probability for the foreseeable future."

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them and identifies their orbits to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.

More information about asteroids and near-Earth objects is at: http://www.jpl.nasa.gov/asteroidwatch

Source: http://www.nasa.gov

Legless geckos slither using skin ridges

A belly carpeted in flattened ridges may help legless lizards slither. Some geckos have only two tiny tabs for legs, so they wriggle and glide like snakes.

These geckos may propel themselves with microscopic corduroy-like ribs on their skin, Marlene Spinner of the University of Kiel in Germany and colleagues suggest October 9 in the Proceedings of the Royal Society B. Unlike geckos with legs, which owe their sticky grip to spines on the skin, the flap-footed lizard Lialis jicari is spine-free where skin skims the ground.

Instead, the reptile carries blunt nubs on the chin and rows of orderly ripples on the stomach, the team discovered by examining freshly shed skin under a microscope. The skin ribs could reduce friction as the animals slide forward.

Source: www.sciencenews.org

Voyager's view

It’s finally official: Voyager 1 has become the first human-made object to enter interstellar space, mission scientists report September 12 in Science. On August 25, 2012, the scientists say, Voyager 1 exited a giant invisible bubble called the heliosphere that is inflated by a torrent of subatomic particles spewing from the sun. Now the probe is surrounded almost exclusively by particles produced by other stars. But whether it’s correct to say that the probe has left the solar system depends on how you define the solar system. “From my perspective, Voyager is nowhere near the edge of the solar system,” says planetary scientist Hal Levison of the Southwest Research Institute in Boulder, Colo. The sun continues to exert gravitational dominance out to hundreds of times the distance of Voyager 1 from the sun, where trillions of icy pebbles, boulders and comets orbit. In the last 36 years, Voyager has traveled an impressive 25.4 billion kilometers, but it still has a long way to go to unambiguously depart the solar system.

Source: www.sciencenews.org

A beacon illuminates a key Alzheimer's protein

By Laura Sanders

Web edition: September 18, 2013

Deep within the living brain, a newly created beacon can illuminate hidden signs of Alzheimer’s disease. Recent work has focused on detecting amyloid, a sticky substance that builds up in the brains of people living with Alzheimer’s. But until now, clinicians lacked a good way to see amyloid’s co-conspirator, the protein called tau. Tangles of a harmful form of tau pile up inside the brains of people with Alzheimer’s disease and several other dementias.

Masahiro Maruyama of the National Institute of Radiological Sciences in Japan and colleagues report September 18 in Neuron that a class of molecules can latch on to tau tangles. When linked to radioactive carbon, these molecules serve as beacons that illuminate tau during PET scans. Scientists know from work with cadavers that the hippocampus harbors tau as Alzheimer’s disease progresses. The new imaging tool will help scientists diagnose and study Alzheimer’s disease and other disorders marked by tau accumulation in living people, the researchers write.

Source: www.sciencenews.org

Cygnus En Route for Sunday Rendezvous With Station

While the newest commercial cargo vehicle to join the International Space Station’s resupply fleet launched Wednesday morning on its demonstration flight, the Expedition 37 crew aboard the orbiting complex was hard at work with medical research, emergency simulation training and preparations for Sunday’s arrival of the new space freighter.

NASA commercial space partner Orbital Sciences Corp. of Dulles, Va., launched its Cygnus cargo spacecraft aboard its Antares rocket at 10:58 a.m. EDT Wednesday from the Mid-Atlantic Regional Spaceport Pad-0A at NASA’s Wallops Flight Facility in Virginia. At the time of launch, the space station was flying about 261 miles above the southern Indian Ocean. Cygnus will rendezvous with the station on Sunday on its demonstration mission to deliver 1,300 pounds of cargo, including food and clothing, to the space station's Expedition 37 crew.

All three Expedition 37 crew members -- Commander Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano -- gathered around a laptop computer screen in the station’s Destiny laboratory to watch a live video stream of the launch of Cygnus. Nyberg then sent her congratulations to Orbital Sciences via her Twitter account, @AstroKarenN.

Nyberg and Parmitano began their workday aboard the space station reviewing Cygnus’ cargo manifest and discussing with ground teams the plan to unload the cargo.  During the month that Cygnus is berthed to the station, the crew will unload its 1,300 pounds of cargo and reload it with trash for disposal when Cygnus departs for a destructive re-entry in the Earth’s atmosphere. The two astronauts then moved on to some on-board training to review the installation procedure for Cygnus. When Cygnus nears the station on Sunday, Parmitano, with assistance from Nyberg, will use the robotics workstation in the cupola to command the station’s 57-foot robotic arm, Canadarm2, to reach out and grapple the vehicle. He will then maneuver the arm to guide Cygnus to its docking port on the Earth-facing side of the Harmony node for installation.

All three Expedition 37 crew members participated in on-board training to review their roles and responsibilities in the event of an emergency aboard the station such as a fire or rapid depressurization. Afterward, they tagged up with flight controllers at Mission Control in Houston to review the drill and discuss any changes needed. Nyberg and Parmitano wrapped up their workday with another round of medical tests for the Ocular Health study as they used a fundoscope to examine each other’s eyes in detail. Vision changes have been observed in some astronauts returning from long-duration spaceflight, and flight surgeons are seeking to learn more about its root causes and develop countermeasures to minimize this risk.

Source: www.nasa.gov

Heliophysics Nugget: Mapping Tons of Meteoric Dust in the Sky

Heliophysics nuggets are a collection of early science results, new research techniques, and instrument updates that further our attempt to understand the sun and the dynamic space weather system that surrounds Earth. On Aug.11 and 12, 2013, the annual Perseid meteor shower will peak, filling the sky with streaks of light, commonly known as shooting stars. Such visually stunning showers are actually but the tip of the iceberg when it comes to meteoroids slamming into Earth's atmosphere: Some 10 to 40 tons of material of invisible meteoric dust enters the atmosphere from interplanetary space every day.

The big showers like the Perseids, and later the Leonids in November, are caused when Earth and its atmosphere travels through a region of the sky filled with left over debris lost by a particular comet. In the case of the Perseids, the small fragments were ripped of the tail of comet Swift-Tuttle, which orbits the sun once every 130 years. The fragments light up due to the immense friction created when they plough into the gas surrounding Earth. Each such fragment is approximately the size of a dime, but the more constant, sporadic meteoroids have been around much longer, breaking down over time into tiny fragments only about as wide as a piece of human hair.

"This is interplanetary dust," said Diego Janches, who studies micrometeoroids at NASA's Goddard Space Flight Center in Greenbelt, Md. "The fragments are either remnants from the solar system's formation, or they are produced by collisions between asteroids or comets from long ago". Janches researches such tiny meteoroids using radar systems set up around the globe, in places such as Sweden, Puerto Rico and Alaska, or the radar system he deployed and operates in Tierra Del Fuego, Argentina. These fragments plough into Earth's atmosphere at speeds of between 7 to 44 miles per second. They also bring with them minerals and metals from their parent bodies, such as sodium, silicon, calcium and magnesium.

"The small meteoroids feed the atmosphere with all these extra materials," Janches said. "They come in, release metallic atoms that get deposited in the mesosphere and then get pushed around from pole to pole by the general global circulation. So by using the metals as tracers, you can answer some important questions about the general composition and movement of the atmosphere." The radar systems set up around the world can track such motion. The meteors collide with atoms in the atmosphere and leave behind a path of electrons and charged particles. This electrically charged region acts as a perfect mirror for radar waves, so the radar bounces back carrying both position information and Doppler shift information. This can be used to measure speed and direction of the background atmospheric winds at the altitudes where the meteoric tails are produced, between 40 and 60 miles high in the sky. Because there are so many such trails, they can be used to measure the velocity and direction of the winds continuously, helping to map out very complex wind patterns on a minute-by-minute basis.

Similar techniques, but using lasers, can be used to map how something like sodium sweeps through the entire atmosphere, thus tracing the global circulation system. This system also sweeps the meteoric dust to the poles where, during the summertime, they can serve as nuclei for ice crystals in the sky forming what's called night-shining or noctilucent clouds.

Source: http://www.nasa.gov