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

Curiosity Makes Its Longest One-Day Drive on Mars

PASADENA, Calif. – NASA's Mars rover Curiosity drove twice as far on July 21 as on any other day of the mission so far: 109.7 yards (100.3 meters). The length of the drive took advantage of starting the 340th Martian day, or sol, of the mission from a location with an unusually good view for rover engineers to plan a safe path. In weeks to come, the rover team plans to begin using "autonav" capability for the rover to autonomously navigate a path for itself, which could make such long drives more frequent.

Curiosity is about three weeks into a multi-month trek, from the "Glenelg" area where it worked for the first half of 2013, to an entry point for the mission's major destination: the lower layers of Mount Sharp. The mission's longest one-day drive prior to July 21 was about 54 yards (49 meters), on Sol 50 (Sept. 26, 2012). After completing the longer drive, Curiosity drove 68.2 yards (62.4 meters) on July 23 (Sol 342), bringing the mission's total driving distance so far to 0.81 mile (1.23 kilometers).

The Sol 340 drive included three segments, with turns at the end of the first and second segments. Rover planners used information from stereo imaging by the Navigation Camera (Navcam) on Curiosity's mast, plus images from the telephoto-lens Mast Camera (Mastcam).  The drive also used the rover's capability to use imagery taken during the drive to calculate the driving distance, a way to verify that wheels have not been slipping too much while turning.

"What enabled us to drive so far on Sol 340 was starting at a high point and also having Mastcam images giving us the size of rocks so we could be sure they were not hazards," said rover planner Paolo Bellutta of NASA's Jet Propulsion Laboratory, Pasadena, Calif. “We could see for quite a distance, but there was an area straight ahead that was not clearly visible, so we had to find a path around that area."

The rover was facing southwest when the sol began. It turned slightly more to the west before driving and used visual odometry to be sure it drove the intended distance (about 55 yards or 50 meters) before turning back farther southward. The second leg, next turn, and third leg completed the drive without visual odometry, though the rover was using another new capability: to turn on visual odometry autonomously if tilt or other factors exceed predetermined limits. New software on Curiosity gives it the capability to use visual odometry through a range of temperatures. This was needed because testing this spring indicated the Navcam pair linked to the rover's B-side computer is more sensitive to temperature than anticipated. Without the compensating software, the onboard analysis of stereo images could indicate different distances to the same point, depending on the temperature at which the images are taken. The rover was switched from its A-side computer to the redundant B-side computer on Feb. 28 due to a flash-memory problem -- subsequently resolved -- on the A-side. The Navcam pair linked to the A-side computer shows less variability with temperature than the pair now in use.

"For now, we're using visual odometry mostly for slip-checking," said JPL's Jennifer Trosper, deputy project manager for Curiosity. "We are validating the capability to begin using autonav at different temperatures." The autonomous navigation capability will enable rover planners to command drives that go beyond the route that they can confirm as safe from previous-sol images. They can tell the rover to use the autonomous capability to choose a safe path for itself beyond that distance.

Curiosity landed at the "Bradbury Landing" location within Gale Crater on Aug. 6, 2012, EDT and Universal Time (Aug. 5, PDT). From there, the rover drove eastward to the Glenelg area, where it accomplished the mission's major science objective of finding evidence for an ancient wet environment that had conditions favorable for microbial life. The rover's route is now southwestward. At Mount Sharp, in the middle of Gale Crater, scientists anticipate finding evidence about how the ancient Martian environment changed and evolved.

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover. More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at http://www.facebook.com/marscuriosity and on Twitter at http://www.twitter.com/marscuriosity .

Source: http://www.nasa.gov

Telescope Door on IRIS Solar Observatory Opens

Today at 11:14 pm PDT (2:14 pm EDT) the IRIS Lockheed Martin instrument team successfully opened the door on NASA’s Interface Region Imaging Spectrograph, which launched June 27, 2013, aboard a Pegasus XL rocket from Vandenberg Air Force Base, Calif. A 60-day check out period began at launch. The first 30 days, which ends July 27, consists of tests and spacecraft system checks. The team will use the remaining 30 days for initial observing runs to fine tune instrument observations. If all is nominal, the team plans to begin normal science mode by August 26.

All data will be available to scientists and the public as soon as the mission begins science operations. The team is looking forward to receiving high-resolution images and spectra soon after first light. Additional mission updates will be provided as warranted.

Large Coronal Hole Near the Sun’s North Pole

The European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, captured this image of a gigantic coronal hole hovering over the sun’s north pole on July 18, 2013, at 9:06 a.m. EDT. Coronal holes are dark, low density regions of the sun’s outermost atmosphere, the corona. They contain little solar material, have lower temperatures, and therefore, appear much darker than their surroundings.

Coronal holes are a typical feature on the sun, though they appear at different places and with more frequency at different times of the sun’s activity cycle. The activity cycle is currently ramping up toward what is known as solar maximum, currently predicted for late 2013. During this portion of the cycle, the number of coronal holes decreases. During solar max, the magnetic fields on the sun reverse and new coronal holes appear near the poles with the opposite magnetic alignment. The coronal holes then increase in size and number, extending further from the poles as the sun moves toward solar minimum again.  At such times, coronal holes have appeared that are even larger than this one.

The holes are important to our understanding of space weather, as they are the source of a high-speed wind of solar particles that streams off the sun some three times faster than the slower wind elsewhere. While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere.

Source: http://www.nasa.gov

Comet Ison Brings Holiday Fireworks

This July Fourth the solar system is showing off some fireworks of its own. Superficially resembling a skyrocket, comet ISON is hurtling toward the sun presently at a whopping 48,000 mph. Its swift motion is captured in this time-lapse movie made from a sequence of pictures taken May 8, 2013, by NASA’s Hubble Space Telescope. At the time the images were taken, the comet was 403 million miles from Earth, between the orbits of Mars and Jupiter.

The movie shows a sequence of Hubble observations taken over a 43-minute span and compresses this into just five seconds. The comet travels 34,000 miles in this brief video, or 7 percent of the distance between Earth and the moon. The deep-space visitor streaks silently against the background stars. Unlike a firework, the comet is not combusting, but in fact is pretty cold. Its skyrocket-looking tail is really a streamer of gas and dust bleeding off the icy nucleus, which is surrounded by a bright star-like-looking coma. The pressure of the solar wind sweeps the material into a tail, like a breeze blowing a windsock.

As the comet warms as it moves closer to the sun, its rate of sublimation (a process similar to evaporation in which solid matter transitions directly into gas) will increase. The comet will get brighter and its tail will grow longer. The comet is predicted to reach naked-eye visibility in November. The comet is named after the organization that discovered it, the Russia-based International Scientific Optical Network. This false-color, visible-light image was taken with Hubble’s Wide Field Camera 3.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy Inc., in Washington, D.C.

Source: http://www.nasa.gov