More Asteroids Could Have Made Life's Ingredients

A wider range of asteroids were capable of creating the kind of amino acids used by life on Earth, according to new NASA research.

Amino acids are used to build proteins, which are used by life to make structures like hair and nails, and to speed up or regulate chemical reactions. Amino acids come in two varieties that are mirror images of each other, like your hands. Life on Earth uses the left-handed kind exclusively. Since life based on right-handed amino acids would presumably work fine, scientists are trying to find out why Earth-based life favored left-handed amino acids

In March, 2009, researchers at NASA's Goddard Space Flight Center in Greenbelt, Md., reported the discovery of an excess of the left-handed form of the amino acid isovaline in samples of meteorites that came from carbon-rich asteroids. This suggests that perhaps left-handed life got its start in space, where conditions in asteroids favored the creation of left-handed amino acids. Meteorite impacts could have supplied this material, enriched in left-handed molecules, to Earth. The bias toward left-handedness would have been perpetuated as this material was incorporated into emerging life.

In the new research, the team reports finding excess left-handed isovaline (L-isovaline) in a much wider variety of carbon-rich meteorites. "This tells us our initial discovery wasn't a fluke; that there really was something going on in the asteroids where these meteorites came from that favors the creation of left-handed amino acids," says Dr. Daniel Glavin of NASA Goddard. Glavin is lead author of a paper about this research published online in Meteoritics and Planetary Science January 17.

"This research builds on over a decade of work on excesses of left-handed isovaline in carbon-rich meteorites," said Dr. Jason Dworkin of NASA Goddard, a co-author on the paper.

"Initially, John Cronin and Sandra Pizzarello of Arizona State University showed a small but significant excess of L-isovaline in two CM2 meteorites. Last year we showed that L-isovaline excesses appear to track with the history of hot water on the asteroid from which the meteorites came. In this work we have studied some exceptionally rare meteorites which witnessed large amounts of water on the asteroid. We were gratified that the meteorites in this study corroborate our hypothesis," explained Dworkin.

"Initially, John Cronin and Sandra Pizzarello of Arizona State University showed a small but significant excess of L-isovaline in two CM2 meteorites. Last year we showed that L-isovaline excesses appear to track with the history of hot water on the asteroid from which the meteorites came. In this work we have studied some exceptionally rare meteorites which witnessed large amounts of water on the asteroid. We were gratified that the meteorites in this study corroborate our hypothesis," explained Dworkin.

L-isovaline excesses in these additional water-altered type 1 meteorites (i.e. CM1 and CR1) suggest that extra left-handed amino acids in water-altered meteorites are much more common than previously thought, according to Glavin. Now the question is what process creates extra left-handed amino acids. There are several options, and it will take more research to identify the specific reaction, according to the team.

However, "liquid water seems to be the key," notes Glavin. "We can tell how much these asteroids were altered by liquid water by analyzing the minerals their meteorites contain. The more these asteroids were altered, the greater the excess L-isovaline we found. This indicates some process involving liquid water favors the creation of left-handed amino acids."

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NASA Comet Hunter Spots Its Valentine

NASA's Stardust spacecraft has downlinked its first images of comet Tempel 1, the target of a flyby planned for Valentine's Day, Feb. 14. The images were taken on Jan. 18 and 19 from a distance of 26.3 million kilometers (16.3 million miles), and 25.4 million kilometers (15.8 million miles) respectively. On Feb. 14, Stardust will fly within about 200 kilometers (124 miles) of the comet's nucleus.

"This is the first of many images to come of comet Tempel 1," said Joe Veverka, principal investigator of NASA's Stardust-NExT mission from Cornell University, Ithaca, N.Y. "Encountering something as small and fast as a comet in the vastness of space is always a challenge, but we are very pleased with how things are setting up for our Valentine's Day flyby."

The composite image is a combination of several images taken by Stardust's navigation camera. Future images will be used to help mission navigators refine Stardust's trajectory, or flight path, as it closes the distance between comet and spacecraft at a rate of about 950,000 kilometers (590,000 miles) a day. On the night of encounter, the navigation camera will be used to acquire 72 high-resolution images of the comet's surface features. Stardust-NExT mission scientists will use these images to see how surface features on comet Tempel 1 have changed over the past five-and-a-half years. (Tempel 1 had previously been visited and imaged in July of 2005 by NASA's Deep Impact mission).

Launched on Feb. 7, 1999, Stardust became the first spacecraft in history to collect samples from a comet (comet Wild 2), and return them to Earth for study. While its sample return capsule parachuted to Earth in January 2006, mission controllers were placing the still-viable spacecraft on a path that would allow NASA the opportunity to re-use the already-proven flight system if a target of opportunity presented itself. In January 2007, NASA re-christened the mission "Stardust-NExT" (New Exploration of Tempel), and the Stardust team began a four-and-a-half year journey for the spacecraft to comet Tempel 1. This will be the second exploration of Tempel 1 by a spacecraft (Deep Impact).

Along with the high-resolution images of the comet's surface, Stardust-NExT will also measure the composition, size distribution and flux of dust emitted into the coma, and provide important new information on how Jupiter-family comets evolve and how they formed 4.6 billion years ago.

Stardust-NExT is a low-cost mission that will expand the investigation of comet Tempel 1 initiated by NASA's Deep Impact spacecraft. JPL, a division of the California Institute of Technology in Pasadena, manages Stardust-NExT for the NASA Science Mission Directorate, Washington, D.C. Joe Veverka of Cornell University, Ithaca, N.Y., is the mission's principal investigator. Lockheed Martin Space Systems, Denver, built the spacecraft and manages day-to-day mission operation

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Runaway Star Plows Through Space

A massive star flung away from its former companion is plowing through space dust. The result is a brilliant bow shock, seen here as a yellow arc in a new image from NASA's Wide-field Infrared Survey Explorer, or WISE.

The star, named Zeta Ophiuchi, is huge, with a mass of about 20 times that of our sun. In this image, in which infrared light has been translated into visible colors we see with our eyes, the star appears as the blue dot inside the bow shock.

Zeta Ophiuchi once orbited around an even heftier star. But when that star exploded in a supernova, Zeta Ophiuchi shot away like a bullet. It's traveling at a whopping 54,000 miles per hour (or 24 kilometers per second), and heading toward the upper left area of the picture.

As the star tears through space, its powerful winds push gas and dust out of its way and into what is called a bow shock. The material in the bow shock is so compressed that it glows with infrared light that WISE can see. The effect is similar to what happens when a boat speeds through water, pushing a wave in front of it.

This bow shock is completely hidden in visible light. Infrared images like this one from WISE are therefore important for shedding new light on the region.

JPL manages and operates WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by NASA's Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA

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NASA's First Solar Sail NanoSail-D Deploys in Low-Earth Orbit

HUNTSVILLE, Ala. – Friday, Jan. 21 at 10 a.m. EST, engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., confirmed that the NanoSail-D nanosatellite deployed its 100-square-foot polymer sail in low-Earth orbit and is operating as planned. Actual deployment occurred on Jan. 20 at 10 p.m. EST and was confirmed today with beacon packets data received from NanoSail-D and additional ground-based satellite tracking assets. In addition, the NanoSail-D orbital parameter data set shows an appropriate change which is consistent with sail deployment.

"This is tremendous news and the first time NASA has deployed a solar sail in low-Earth orbit," said Dean Alhorn, NanoSail-D principal investigator and aerospace engineer at the Marshall Center. "To get to this point is an incredible accomplishment for our small team and I can't thank the amateur ham operator community enough for their help in tracking NanoSail-D. Their assistance was invaluable. In particular, the Marshall Amateur Radio Club was the very first to hear the radio beacon. It was exciting!"

NanoSail-D will continue to send out beacon signals until the onboard batteries are expended and can be found at 437.270 MHz. It can be tracked on the NanoSail-D dashboard at: http://nanosaild.engr.scu.edu/dashboard.htm.

It is estimated that NanoSail-D will remain in low-Earth orbit between 70 and 120 days, depending on atmospheric conditions. NanoSail-D is designed to demonstrate deployment of a compact solar sail boom technology. This research demonstration could lead to further advances of this alternative solar sail propulsion and the critical need for new de-orbit technologies. This ejection experiment also demonstrates a spacecraft’s ability, like the Fast, Affordable, Science and Technology Satellite, or FASTSAT, to eject a nano-satellite from a micro-satellite, while avoiding re-contact with the primary satellite.

"This is a significant accomplishment for both the FASTSAT and NanoSail-D projects. This accomplishment validates that we've met another of our primary mission objectives -- successfully ejecting a nanosatellite from an orbiting microsatellite," said Mark Boudreaux, FASTSAT project manager at the Marshall Center. "This is another significant accomplishment for our inter Agency, Industry and Governmental FASTSAT-HSV01 partnership team."

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Voyager Celebrates 25 Years Since Uranus Visit

As NASA's Voyager 2 spacecraft made the only close approach to date of our mysterious seventh planet Uranus 25 years ago, Project Scientist Ed Stone and the Voyager team gathered at NASA's Jet Propulsion Laboratory, Pasadena, Calif., to pore over the data coming in.

Images of the small, icy Uranus moon Miranda were particularly surprising. Since small moons tend to cool and freeze over rapidly after their formation, scientists had expected a boring, ancient surface, pockmarked by crater-upon-weathered-crater. Instead they saw grooved terrain with linear valleys and ridges cutting through the older terrain and sometimes coming together in chevron shapes. They also saw dramatic fault scarps, or cliffs. All of this indicated that periods of tectonic and thermal activity had rocked Miranda's surface in the past.

The scientists were also shocked by data showing that Uranus's magnetic north and south poles were not closely aligned with the north-south axis of the planet's rotation. Instead, the planet's magnetic field poles were closer to the Uranian equator. This suggested that the material flows in the planet's interior that are generating the magnetic field are closer to the surface of Uranus than the flows inside Earth, Jupiter and Saturn are to their respective surfaces.

"Voyager 2's visit to Uranus expanded our knowledge of the unexpected diversity of bodies that share the solar system with Earth," said Stone, who is based at the California Institute of Technology in Pasadena. "Even though similar in many ways, the worlds we encounter can still surprise us."

Voyager 2 was launched on Aug. 20, 1977, 16 days before its twin, Voyager 1. After completing its prime mission of flying by Jupiter and Saturn, Voyager 2 was sent on the right flight path to visit Uranus, which is about 3 billion kilometers (2 billion miles) away from the sun. Voyager 2 made its closest approach – within 81,500 kilometers (50,600 miles) of the Uranian cloud tops – on Jan. 24, 1986.

Before Voyager 2's visit, scientists had to learn about Uranus by using Earth-based and airborne telescopes. By observing dips in starlight as a star passed behind Uranus, scientists knew Uranus had nine narrow rings. But it wasn't until the Voyager 2 flyby that scientists were able to capture for the first time images of the rings and the tiny shepherding moons that sculpted them. Unlike Saturn's icy rings, they found Uranus' rings to be dark gray, reflecting only a few percent of the incident sunlight

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Cosmonauts to Perform 27th Russian Space Station Spacewalk

Two Russian cosmonauts will venture outside the International Space Station on Jan. 21 to complete installation of a new high-speed data transmission system, remove an old plasma pulse experiment, install a camera for the new Rassvet docking module and retrieve a materials exposure package.

Expedition 26 Flight Engineers Dmitry Kondratyev and Oleg Skripochka are scheduled to float outside the Pirs airlock at 9:20 a.m. EST to begin the six-hour excursion. Both spacewalkers will wear Russian Orlan-MK spacesuits.

Kondratyev will be designated as Extravehicular 1 (EV1), with a red stripe on his suit, and Skripochka will be EV2, with a blue stripe on his suit. Skripochka also will wear a NASA-provided wireless television camera system and helmet lights to provide live point-of-view video to Mission Control-Moscow, which will provide ground support for the spacewalk. Mission Control-Houston will monitor the spacewalk as well.

Before the spacewalk begins, Commander Scott Kelly and Flight Engineer Alexander Kaleri will climb into their Soyuz 24 spacecraft, which is docked to the Poisk module on the opposite side of Zvezda from the airlock, and seal the hatches between Zvezda and Poisk. This protects against the unlikely possibility of a sudden station depressurization and also allows for the use of the forward portion of Zvezda as a backup airlock if necessary. Flight Engineers Cady Coleman and Paolo Nespoli will be in the U.S. segment and will have access to their Soyuz 25 spacecraft, which is docked to the Rassvet module adjacent to Pirs on the Zarya control module, therefore they do not need to be sequestered.

As a sunrise dawns on the station, Kondratyev and Skripochka will open the Pirs hatch and begin exiting the Russian segment of the station. They’ll take with them a spacewalk tool carrier, an antenna and cable reel for the data transmission system, and protective covers for the experiments they will bring back inside the station. All will be temporarily affixed to the Zvezda service module’s exterior for handy access near the respective work sites.

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NASA Tests New Propulsion System For Robotic Lander Prototype

HUNTSVILLE, Ala. – NASA's Robotic Lunar Lander Development Project at Marshall Space Flight Center in Huntsville, Ala., has completed a series of hot fire tests and taken delivery of a new propulsion system for integration into a more sophisticated free-flying autonomous robotic lander prototype. The project is partnered with the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., to develop a new generation of small, smart, versatile robotic landers to achieve scientific and exploration goals on the surface of the moon and near-Earth asteroids.

The new robotic lander prototype will continue to mature the development of a robotic lander capability by bringing online an autonomous flying test lander that will be capable of flying up to sixty seconds, testing the guidance, navigation and control system by demonstrating a controlled landing in a simulated low gravity environment.

By the spring of 2011, the new prototype lander will begin flight tests at the U.S. Army's Redstone Arsenal Test Center in Huntsville, Ala.

The prototype’s new propulsion system consists of 12 small attitude control thrusters, three primary descent thrusters to control the vehicle’s altitude, and one large "gravity-canceling" thruster which offsets a portion of the prototype’s weight to simulate a lower gravity environment, like that of the moon and asteroids. The prototype uses a green propellant, hydrogen peroxide, in a stronger concentration of a solution commonly used in homes as a disinfectant. The by-products after use are water and oxygen.

"The propulsion hardware acceptance test consisted of a series of tests that verified the performance of each thruster in the propulsion system," said Julie Bassler, Robotic Lunar Lander Development Project Manager. "The series culminated in a test that characterized the entire system by running a scripted set of thruster firings based on a flight scenario simulation."

The propulsion system is currently at Teledyne Brown’s manufacturing facility in Huntsville, Ala., for integration with the structure and avionics to complete the new robotic lander prototype. Dynetics Corp. developed the robotic lander prototype propulsion system under the management of the Von Braun Center for Science and Innovation both located in Huntsville, Ala.

"This is the second phase of a robotic lander prototype development program," said Bassler. "Our initial "cold gas" prototype was built, delivered and successfully flight tested at the Marshall Center in a record nine months, providing a physical and tangible demonstration of capabilities related to the critical terminal descent and landing phases for an airless body mission."

The first robotic lander prototype has a record flight time of ten seconds and descended from three meters altitude. This first robotic lander prototype began flight tests in September 2009 and has completed 142 flight tests, providing a platform to develop and test algorithms, sensors, avionics, ground and flight software and ground systems to support autonomous landings on airless bodies, where aero-braking and parachutes are not options.

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GOES-13 Satellite Captures Powerful Snowmaker Leaving New England

Snows are finally winding down in New England today, Dec. 27, as a powerful low pressure system brought blizzard conditions from northern New Jersey to Maine over Christmas weekend. The GOES-13 satellite captured an image of the low's center off the Massachusetts coast and saw the snowfall left behind.

The Geostationary Operational Environmental Satellite called GOES-13 captured the visible image. GOES satellites are operated by the National Oceanic and Atmospheric Administration, and NASA's GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md. creates some of the GOES satellite images and animations.

As of 1:30 p.m. EST, all blizzard warnings were canceled as the low has pulled much of its snow and rain away from land areas and into the North Atlantic Ocean. The winds behind the system are now causing more problems for residents along the U.S. East coast.

Snowfall ranged from 1.5 inches in Atlanta, Georgia to more than a foot in various areas of New Jersey, New York and the New England states. Near Wallops Island, Va. where NASA has a facility, more than 11 inches of snow was reported this morning. Newark, N.J. reported 17.7 inches of snow by midnight last night. Central Park in New York City reported 12.0 inches of snow had fallen just before midnight. Providence, Rhode Island reported 7.9 inches by midnight, while Boston, Mass. reported 9.9 inches at that time. More snow fell on top of those totals during the morning hours today.

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Cassini Rocks Rhea Rendezvous

NASA's Cassini spacecraft has successfully completed its closest flyby of Saturn's moon Rhea, returning raw images of the icy moon's surface.

Pictures of the Rhea surface taken around the time of closest approach at 4:53 a.m. UTC on Jan. 11, 2011, which was 10:53 p.m. PST, Jan. 10, show shadowy craters at a low sun angle. A portrait of bright, icy Rhea also captures Saturn's rings and three other moons clearly visible in the background.

Images obtained by Cassini's imaging science subsystem show an old, inert surface saturated with craters, just like the oldest parts of Earth's moon. But there appear to be some straight faults that were formed early in Rhea's history, which never developed the full-blown activity seen on another of Saturn's moons, Enceladus.

The flyby of Rhea also presented scientists with their best available chance to study how often tiny meteoroids bombard the moon's surface. Scientists are now sifting through data collected on the close flyby by the cosmic dust analyzer and the radio and plasma wave science instrument. They will use the data to deduce how often objects outside the Saturn system contaminate Saturn's rings, and to improve estimates of how old the rings are.

Scientists using Cassini's fields and particles instruments are also looking through their data to see if they learned more about Rhea's very thin oxygen-and-carbon-dioxide atmosphere and the interaction between Rhea and the particles within Saturn's magnetosphere, the magnetic bubble around the planet.

At closest approach, Cassini passed within about 69 kilometers (43 miles) of the surface.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

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The Two-faced Whirlpool Galaxy

These images by NASA's Hubble Space Telescope show off two dramatically different face-on views of the spiral galaxy M51, dubbed the Whirlpool Galaxy.

The image at left, taken in visible light, highlights the attributes of a typical spiral galaxy, including graceful, curving arms, pink star-forming regions, and brilliant blue strands of star clusters.

In the image at right, most of the starlight has been removed, revealing the Whirlpool's skeletal dust structure, as seen in near-infrared light. This new image is the sharpest view of the dense dust in M51. The narrow lanes of dust revealed by Hubble reflect the galaxy's moniker, the Whirlpool Galaxy, as if they were swirling toward the galaxy's core.

To map the galaxy's dust structure, researchers collected the galaxy's starlight by combining images taken in visible and near-infrared light. The visible-light image captured only some of the light; the rest was obscured by dust. The near-infrared view, however, revealed more starlight because near-infrared light penetrates dust. The researchers then subtracted the total amount of starlight from both images to see the galaxy's dust structure.

The red color in the near-infrared image traces the dust, which is punctuated by hundreds of tiny clumps of stars, each about 65 light-years wide. These stars have never been seen before. The star clusters cannot be seen in visible light because dense dust enshrouds them. The image reveals details as small as 35 light-years across.

Astronomers expected to see large dust clouds, ranging from about 100 light-years to more than 300 light-years wide. Instead, most of the dust is tied up in smooth and diffuse dust lanes. An encounter with another galaxy may have prevented giant clouds from forming.

Probing a galaxy's dust structure serves as an important diagnostic tool for astronomers, providing invaluable information on how the gas and dust collapse to form stars. Although Hubble is providing incisive views of the internal structure of galaxies such as M51, the planned James Webb Space Telescope (JWST) is expected to produce even crisper images.

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NASA Telescopes Help Find Most Distant Galaxy Cluster

PASADENA, Calif. -- Astronomers have uncovered a burgeoning galactic metropolis, the most distant known in the early universe. This ancient collection of galaxies presumably grew into a modern galaxy cluster similar to the massive ones seen today.

The developing cluster, named COSMOS-AzTEC3, was discovered and characterized by multi-wavelength telescopes, including NASA's Spitzer, Chandra and Hubble space telescopes, and the ground-based W.M. Keck Observatory and Japan's Subaru Telescope.

"This exciting discovery showcases the exceptional science made possible through collaboration among NASA projects and our international partners," said Jon Morse, NASA's Astrophysics Division director at NASA Headquarters in Washington.

Scientists refer to this growing lump of galaxies as a proto-cluster. COSMOS-AzTEC3 is the most distant massive proto-cluster known, and also one of the youngest, because it is being seen when the universe itself was young. The cluster is roughly 12.6 billion light-years away from Earth. Our universe is estimated to be 13.7 billion years old. Previously, more mature versions of these clusters had been spotted at 10 billion light-years away.

The astronomers also found that this cluster is buzzing with extreme bursts of star formation and one enormous feeding black hole.

"We think the starbursts and black holes are the seeds of the cluster," said Peter Capak of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena. "These seeds will eventually grow into a giant, central galaxy that will dominate the cluster -- a trait found in modern-day galaxy clusters." Capak is first author of a paper appearing in the Jan. 13 issue of the journal Nature.

Most galaxies in our universe are bound together into clusters that dot the cosmic landscape like urban sprawls, usually centered around one old, monstrous galaxy containing a massive black hole. Astronomers thought that primitive versions of these clusters, still forming and clumping together, should exist in the early universe. But locating one proved difficult—until now.

Capak and his colleagues first used the Chandra X-ray Observatory and the United Kingdom's James Clerk Maxwell Telescope on Mauna Kea, Hawaii, to search for the black holes and bursts of star formation needed to form the massive galaxies at the centers of modern galaxy cities. The astronomers then used the Hubble and Subaru telescopes to estimate the distances to these objects, and look for higher densities of galaxies around them. Finally, the Keck telescope was used to confirm that these galaxies were at the same distance and part of the same galactic sprawl.

Once the scientists found this lumping of galaxies, they measured the combined mass with the help of Spitzer. At this distance, the optical light from stars is shifted, or stretched, to infrared wavelengths that can only be observed in outer space by Spitzer. The lump sum of the mass turned out to be a minimum of 400 billion suns -- enough to indicate that the astronomers had indeed uncovered a massive proto-cluster. The Spitzer observations also helped confirm that a massive galaxy at the center of the cluster was forming stars at an impressive rate.

Chandra X-ray observations were used to find and characterize the whopping black hole with a mass of more than 30 million suns. Massive black holes are common in present-day galaxy clusters, but this is the first time a feeding black hole of this heft has been linked to a cluster that is so young.

Finally, the Institut de Radioastronomie Millimétrique's interferometer telescope in France and 30-meter (about 100-foot) telescope in Spain, along with the National Radio Astronomy Observatory's Very Large Array telescope in New Mexico, measured the amount of gas, or fuel for future star formation, in the cluster. The results indicate the cluster will keep growing into a modern city of galaxies.

"It really did take a village of telescopes to nail this cluster," said Capak. "Observations across the electromagnetic spectrum, from X-ray to millimeter wavelengths, were all critical in providing a comprehensive view of the cluster's many facets."

COSMOS-AzTEC3, located in the constellation Sextans, is named after the region where it was found, called COSMOS after the Cosmic Evolution Survey. AzTEC is the name of the camera used on the James Clerk Maxwell Telescope; this camera is now on its way to the Large Millimeter Telescope located in Mexico's Puebla state

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NASA Research Team Reveals Moon Has Earth-Like Core

State-of-the-art seismological techniques applied to Apollo-era data suggest our moon has a core similar to Earth's.

Uncovering details about the lunar core is critical for developing accurate models of the moon's formation. The data sheds light on the evolution of a lunar dynamo -- a natural process by which our moon may have generated and maintained its own strong magnetic field.

The team's findings suggest the moon possesses a solid, iron-rich inner core with a radius of nearly 150 miles and a fluid, primarily liquid-iron outer core with a radius of roughly 205 miles. Where it differs from Earth is a partially molten boundary layer around the core estimated to have a radius of nearly 300 miles. The research indicates the core contains a small percentage of light elements such as sulfur, echoing new seismology research on Earth that suggests the presence of light elements -- such as sulfur and oxygen -- in a layer around our own core.

The researchers used extensive data gathered during the Apollo-era moon missions. The Apollo Passive Seismic Experiment consisted of four seismometers deployed between 1969 and 1972, which recorded continuous lunar seismic activity until late-1977.


"We applied tried and true methodologies from terrestrial seismology to this legacy data set to present the first-ever direct detection of the moon's core," said Renee Weber, lead researcher and space scientist at NASA's Marshall Space Flight Center in Huntsville, Ala.

In addition to Weber, the team consisted of scientists from Marshall; Arizona State University; the University of California at Santa Cruz; and the Institut de Physique du Globe de Paris in France. Their findings are published in the online edition of the journal Science.

The team also analyzed Apollo lunar seismograms using array processing, techniques that identify and distinguish signal sources of moonquakes and other seismic activity. The researchers identified how and where seismic waves passed through or were reflected by elements of the moon's interior, signifying the composition and state of layer interfaces at varying depths.

Although sophisticated satellite imaging missions to the moon made significant contributions to the study of its history and topography, the deep interior of Earth's sole natural satellite remained a subject of speculation and conjecture since the Apollo era. Researchers previously had inferred the existence of a core, based on indirect estimates of the moon's interior properties, but many disagreed about its radius, state and composition.

A primary limitation to past lunar seismic studies was the wash of "noise" caused by overlapping signals bouncing repeatedly off structures in the moon's fractionated crust. To mitigate this challenge, Weber and the team employed an approach called seismogram stacking, or the digital partitioning of signals. Stacking improved the signal-to-noise ratio and enabled the researchers to more clearly track the path and behavior of each unique signal as it passed through the lunar interior.

"We hope to continue working with the Apollo seismic data to further refine our estimates of core properties and characterize lunar signals as clearly as possible to aid in the interpretation of data returned from future missions," Weber said.

Future NASA missions will help gather more detailed data. The Gravity Recovery and Interior Laboratory, or GRAIL, is a NASA Discovery-class mission set to launch this year. The mission consists of twin spacecraft that will enter tandem orbits around the moon for several months to measure the gravity field in unprecedented detail. The mission also will answer longstanding questions about Earth's moon and provide scientists a better understanding of the satellite from crust to core, revealing subsurface structures and, indirectly, its thermal history.

NASA and other space agencies have been studying concepts to establish an International Lunar Network -- a robotic set of geophysical monitoring stations on the moon -- as part of efforts to coordinate international missions during the coming decade.

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NASA's Hubble Finds that Puny Stars Pack a Big Punch

A deep survey of more than 200,000 stars in our Milky Way galaxy has unveiled the sometimes petulant behavior of tiny red dwarf stars. These stars, which are smaller than the Sun, can unleash powerful eruptions called flares that may release the energy of more than 100 million atomic bombs.

Red dwarfs are the most abundant stars in our universe and are presumably hosts to numerous planets. However, their erratic behavior could make life unpleasant, if not impossible, for many alien worlds. Flares are sudden eruptions of heated plasma that occur when powerful magnetic field lines in a star's atmosphere "reconnect," snapping like a rubber band and releasing vast amounts of energy. When they occur, flares would blast any planets orbiting the star with ultraviolet light, bursts of X-rays, and a gush of charged particles called a stellar wind.

Studying the light from 215,000 red dwarfs collected in observations by NASA's Hubble Space Telescope, astronomers found 100 stellar flares. The observations, taken over a seven-day period, constitute the largest continuous monitoring of red dwarf stars ever undertaken.

"We know that hyperactive young stars produce flares, but this study shows that even in fairly old stars that are several billion years old, flares are a fact of life," says astronomer Rachel Osten of the Space Telescope Science Institute in Baltimore, Md., leader of the research team. "Life could be rough for any planets orbiting close enough to these flaring stars. Their heated atmospheres could puff up and might get stripped away."

Osten and her team, including Adam Kowalski of the University of Washington in Seattle, found that the red dwarf stars flared about 15 times less frequently than in previous surveys, which observed younger and less massive stars.

The stars in this study were originally part of a search for planets. Hubble monitored the stars continuously for a week in 2006, looking for the signature of planets passing in front of them. The stars were photographed by Hubble's Advanced Camera for Surveys during the extrasolar-planet survey called the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS).

Osten and Kowalski realized that this powerful census contained important information on the stars themselves, and they took advantage of it. They searched the Hubble data, looking for a slight increase in the brightness of red dwarfs, a signature of flares. Some of the stars grew up to 10 percent brighter over a short period of time, which is actually much brighter than flares on our Sun. The average duration of the flares was 15 minutes. A few stars produced multiple flares.

The astronomers found that stars that periodically oscillate in brightness, called variable stars, were more prone to the short-term outbursts.

"We discovered that variable stars are about a thousand times more likely to flare than non-variable stars," Kowalski says. "The variable stars are rotating fast, which may mean they are in rapidly orbiting binary systems. If the stars possess large star spots, dark regions on a star's surface, that will cause the star's light to vary when the spots rotate in and out of view. Star spots are produced when magnetic field lines poke through the surface. So, if there are big spots, there is a large area covered by strong magnetic fields, and we found that those stars had more flares."

Although red dwarfs are smaller than the Sun, they have a deeper convection zone, where cells of hot gas bubble to the surface, like boiling oatmeal," Osten explains. This zone generates the magnetic field and enables red dwarfs to put out such energetic flares.

"The red dwarfs also have magnetic fields that are stronger than the Sun's," Osten continues. "They cover a much larger area than the Sun. Sunspots cover less than 1 percent of the Sun's surface, while red dwarfs can have star spots that cover half of their surfaces."

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Major Surgery Complete for Deep Space Network Antenna

PASADENA, Calif. –The seven-month upgrade to the historic "Mars antenna" at NASA's Deep Space Network site in Goldstone, Calif. has been completed. After a month of intensive testing, similar to the rehabilitation stage after surgery, the antenna is now ready to help maintain communication with spacecraft during the next decade of space exploration.

The month of October was used as a testing period to make sure the antenna was in working order and fully functional, as scheduled, for Nov. 1. A team of workers completed an intense series of tasks to reach its first milestone – upgrading the 70-meter-wide (230-foot-wide) antenna in time to communicate with the EPOXI mission spacecraft during its planned flyby of comet Hartley 2 on Nov. 4.

The first official demonstration space track was on Sept. 28, when the antenna communicated with NASA's EPOXI mission spacecraft.

"We've been testing the antenna since Sept. 28, and we've had no problems in tracking the spacecraft," said Peter Hames of NASA's Jet Propulsion Laboratory, Pasadena, Calif., who is responsible for maintaining the network's antennas. "We are ready to resume service as scheduled." JPL manages the Deep Space Network for NASA.

During the upgrade process, workers raised a portion of the antenna that weighs 3.2 million kilograms (7 million pounds) up from the base by 5 millimeters (0.2 inches) while they performed a precise, delicate repair. They replaced a portion of the hydrostatic bearing (enabling the antenna to rotate horizontally) and the four elevation bearings (enabling the antenna to track up and down from the horizon).

Unlike the sterile confines of an operating room, this surgery took place in the middle of California's Mojave Desert, a hot oasis baked by the unforgiving desert heat. The team members were able to cheat the heat by completing a number of the 375 tasks during early morning and night shifts. The tasks required the team to analyze, load, lift, install, test, analyze again and inspect.

The Deep Space Network consists of three deep-space communication facilities positioned approximately 120 degrees of longitude apart. In addition to the Mojave Desert location at Goldstone, the other locations are outside of Madrid, Spain, and Canberra, Australia. Each 70-meter (230-foot) antenna is capable of tracking a spacecraft traveling more than 16 billion kilometers (10 billion miles) from Earth. The antennas are strategically situated at each location in semi-mountainous basins to reduce radio frequency interference. This careful placement helps make the Deep Space Network the largest and most sensitive science telecommunications system in the world.

In March 1966, the antenna, officially known as Deep Space Station 14, earned its nickname as the Mars antenna because its first-ever signal came from NASA's Mariner 4 mission to Mars. The historic dish is now responsible for tracking an entire fleet of missions, including the rovers Spirit and Opportunity currently on the surface of Mars, the Cassini orbiter at Saturn, the twin Voyager spacecraft in the outer reaches of our solar system, and the Spitzer Space Telescope, which observes stars, galaxies and other celestial objects.

"We are nearing the completion of a very challenging engineering effort that will extend the life of one of the DSN's workhorses, making it more available and reliable in returning critical science data through at least 2025," said Wayne Sible, the network's deputy project manager at JPL.

The antenna upgrade was a collaborative effort between JPL, Diani Building Corp., Santa Maria, Calif., and ITT Corp., White Plains, N.Y. Their shared goal was to emerge from the "operating room" with a healthy patient.

"The 70-meter antenna gets under your skin, everyone involved in this project was so passionate about it, from the grout workers to the machine shops to the guys on the antenna, everybody was giving it their absolute all," said Hames.

JPL, a division of the California Institute of Technology in Pasadena, manages the Deep Space Network for NASA Headquarters, Washington.

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NASA's LRO Creating Unprecedented Topographic Map of Moon

NASA's Lunar Reconnaissance Orbiter is allowing researchers to create the most precise and complete map to date of the moon's complex, heavily cratered landscape.

"This dataset is being used to make digital elevation and terrain maps that will be a fundamental reference for future scientific and human exploration missions to the moon," said Dr. Gregory Neumann of NASA's Goddard Space Flight Center in Greenbelt, Md. "After about one year taking data, we already have nearly 3 billion data points from the Lunar Orbiter Laser Altimeter on board the LRO spacecraft, with near-uniform longitudinal coverage. We expect to continue to make measurements at this rate through the next two years of the science phase of the mission and beyond. Near the poles, we expect to provide near-GPS-like navigational capability as coverage is denser due to the spacecraft's polar orbit." Neumann will present the map at the American Geophysical Union meeting in San Francisco December 17.


The Lunar Orbiter Laser Altimeter (LOLA) works by propagating a single laser pulse through a Diffractive Optical Element that splits it into five beams. These beams then strike and are backscattered from the lunar surface. From the return pulse, the LOLA electronics determines the time of flight which, accounting for the speed of light, provides a precise measurement of the range from the spacecraft to the lunar surface. Range measurements, combined with accurate tracking of the spacecraft's location, are used to build a map revealing the contours of the lunar landscape. The five beams create a two-dimensional spot pattern that unambiguously reveals slopes. LOLA will also measure the spreading of the return pulse to get the surface roughness and the change in the transmitted compared to the return energy of the pulse to determine surface reflectance.

The new LOLA maps are more accurate and sample more places on the lunar surface than any available before. "The positional errors of image mosaics of the lunar far side, where direct spacecraft tracking – the most accurate -- is unavailable, have been one to ten kilometers (about 0.62 to 6.2 miles)," said Neumann. "We're beating these down to the level of 30 meters (almost 100 feet) or less spatially and one meter (almost 3.3 feet) vertically. At the poles, where illumination rarely provides more than a glimpse of the topography below the crater peaks, we found systematic horizontal errors of hundreds of meters (hundreds of yards) as well." In terms of coverage, the nearly three billion range measurements so far by LRO compare to about eight million to nine million each from three recent international lunar missions, according to Neumann. "They were limited to a mile or so between individual data points, whereas our measurements are spaced about 57 meters (about 187 feet) apart in five adjacent tracks separated by about 15 meters (almost 50 feet)."

"Recent papers have clarified some aspects of lunar processes based solely on the more precise topography provided by the new LOLA maps," adds Neumann, "such as lunar crater density and resurfacing by impacts, or the formation of multi-ring basins."

"The LOLA data also allow us to define the current and historical illumination environment on the moon," said Neumann. Lunar illumination history is important for discovering areas that have been shaded for long periods. Such places, typically in deep craters near the lunar poles, act like cold storage, and are capable of accumulating and preserving volatile material like water ice.

The landscape in polar craters is mysterious because their depths are often in shadow. The new LOLA dataset is illuminating details of their topography for the first time. "Until LRO and the recent Japanese Kaguya mission, we had no idea of what the extremes of polar crater slopes were," said Neumann. "Now, we find slopes of 36 degrees over several kilometers (several thousands of yards) in Shackleton crater, for example, which would make traverses quite difficult and apparently causes landslides. The LOLA measurements of shadowed polar crater slopes and their surface roughness take place at scales from lander size to kilometers. These measurements are helping the LRO science team model the thermal environment of these craters, and team members are developing temperature maps of them."

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Andromeda is So Hot 'n' Cold

This mosaic of the Andromeda spiral galaxy highlights explosive stars in its interior, and cooler, dusty stars forming in its many rings. The image is a combination of observations from the Herschel Space Observatory taken in infrared light (seen in orange hues), and the XMM-Newton telescope captured in X-rays (seen in blues). NASA plays a role in both of these European Space Agency-led missions.

Herschel provides a detailed look at the cool clouds of star birth that line the galaxy's five concentric rings. Massive young stars are heating blankets of dust that surround them, causing them to glow in the longer-wavelength infrared light, known as far-infrared, that Herschel sees.

In contrast, XMM-Newton is capturing what happens at the end of the lives of massive stars. It shows the high-energy X-rays that come from, among other objects, supernova explosions and massive dead stars rotating around companions. These X-ray sources are clustered in the center of the galaxy, where the most massive stars tend to form.

Andromeda is our Milky Way galaxy's nearest large neighbor. It is located about 2.5 million light-years away and holds up to an estimated trillion stars. Our Milky Way is thought to contain about 200 billion to 400 billion stars.

Read more at: http://www.esa.int/SPECIALS/Herschel/SEMY1K0SDIG_0.html .

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.

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