NASA Satellite Sees Tornado Tracks in Tuscaloosa, Alabama

Deadly tornadoes raked across Alabama on April 27, 2011, killing as many as 210 people as of April 29. The hardest-hit community was Tuscaloosa. In an image acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on April 28, three tornado tracks are visible through and around the city.

The tracks are pale brown trails where green trees and plants have been uprooted, leaving disturbed ground. Though faint, the center track runs from southwest of Tuscaloosa, through the gray city, and extends northeast towards Birmingham. Two other tracks run parallel to the center track. The northernmost track is in an area where the National Weather Service reported a tornado, but no tornado was reported in the vicinity of the more visible southern track. In the southern region, strong winds were reported.

The tornadoes were part of a larger weather pattern that produced more than 150 tornadoes across six states, said the National Weather Service. The death toll had nearly reached 300 on April 29, making the outbreak the deadliest in the United States since 1974.

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NASA's Swift and Hubble Probe Asteroid Collision Debris

Late last year, astronomers noticed an asteroid named Scheila had unexpectedly brightened, and it was sporting short-lived plumes. Data from NASA's Swift satellite and Hubble Space Telescope showed these changes likely occurred after Scheila was struck by a much smaller asteroid.

"Collisions between asteroids create rock fragments, from fine dust to huge boulders, that impact planets and their moons," said Dennis Bodewits, an astronomer at the University of Maryland in College Park and lead author of the Swift study. "Yet this is the first time we've been able to catch one just weeks after the smash-up, long before the evidence fades away."

Asteroids are rocky fragments thought to be debris from the formation and evolution of the solar system approximately 4.6 billion years ago. Millions of them orbit the sun between Mars and Jupiter in the main asteroid belt. Scheila is approximately 70 miles across and orbits the sun every five years.

"The Hubble data are most simply explained by the impact, at 11,000 mph, of a previously unknown asteroid about 100 feet in diameter," said Hubble team leader David Jewitt at the University of California in Los Angeles. Hubble did not see any discrete collision fragments, unlike its 2009 observations of P/2010 A2, the first identified asteroid collision.

The studies will appear in the May 20 edition of The Astrophysical Journal Letters and are available online.

Astronomers have known for decades that comets contain icy material that erupts when warmed by the sun. They regarded asteroids as inactive rocks whose destinies, surfaces, shapes and sizes were determined by mutual impacts. However, this simple picture has grown more complex over the past few years.

During certain parts of their orbits, some objects, once categorized as asteroids, clearly develop comet-like features that can last for many months. Others display much shorter outbursts. Icy materials may be occasionally exposed, either by internal geological processes or by an external one, such as an impact.

On Dec. 11, 2010, images from the University of Arizona's Catalina Sky Survey, a project of NASA's Near Earth Object Observations Program, revealed Scheila to be twice as bright as expected and immersed in a faint comet-like glow. Looking through the survey's archived images, astronomers inferred the outburst began between Nov. 11 and Dec. 3.

Three days after the outburst was announced, Swift's Ultraviolet/Optical Telescope (UVOT) captured multiple images and a spectrum of the asteroid. Ultraviolet sunlight breaks up the gas molecules surrounding comets; water, for example, is transformed into hydroxyl and hydrogen. But none of the emissions most commonly identified in comets, such as hydroxyl or cyanogen, show up in the UVOT spectrum. The absence of gas around Scheila led the Swift team to reject scenarios where exposed ice accounted for the activity.

Images show the asteroid was flanked in the north by a bright dust plume and in the south by a fainter one. The dual plumes formed as small dust particles excavated by the impact were pushed away from the asteroid by sunlight. Hubble observed the asteroid's fading dust cloud on Dec. 27, 2010, and Jan. 4, 2011.

The two teams found the observations were best explained by a collision with a small asteroid impacting Scheila's surface at an angle of less than 30 degrees, leaving a crater 1,000 feet across. Laboratory experiments show a more direct strike probably wouldn't have produced two distinct dust plumes. The researchers estimated the crash ejected more than 660,000 tons of dust -- equivalent to nearly twice the mass of the Empire State Building.

"The dust cloud around Scheila could be 10,000 times as massive as the one ejected from comet 9P/Tempel 1 during NASA's UMD-led Deep Impact mission," said co-author Michael Kelley, also at the University of Maryland. "Collisions allow us to peek inside comets and asteroids. Ejecta kicked up by Deep Impact contained lots of ice, and the absence of ice in Scheila's interior shows that it's entirely unlike comets."

NASA's Goddard Space Flight Center in Greenbelt, Md., manages Hubble and Swift. Hubble was built and is operated in partnership with the European Space Agency. Science operations for both missions include contributions from many national and international partners.

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Five Things About NASA's Voyager Mission

Here are five facts about NASA's twin Voyager 1 and 2 spacecraft, the longest continuously-operating spacecraft in deep space. The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both spacecraft.

Long-Distance Space Runners
Voyager 2 launched on Aug. 20, 1977, and Voyager 1 launched about two weeks later, on Sept. 5. Since then, the spacecraft have been traveling along different flight paths and at different speeds. Now some 17.4 billion kilometers (10.8 billion miles) from the sun and hurtling toward interstellar space, Voyager 1 is the farthest human-made object from Earth. Voyager 2 is about 14.2 billion kilometers (8.8 billion miles) from the sun.

Can You Hear Me Now?
Both spacecraft are still sending scientific information about their surroundings through NASA's Deep Space Network. A signal from the ground, traveling at the speed of light, takes about 13 hours one way to reach Voyager 2, and 16 hours one way to reach Voyager 1.

Planetary Tour
The primary five-year mission of the Voyagers included the close-up exploration of Jupiter and Saturn, Saturn's rings and the larger moons of the two planets. The mission was extended after a succession of discoveries, and between them, the two spacecraft have explored all the giant outer planets of our solar system -- Jupiter, Saturn, Uranus and Neptune, 49 moons, and the systems of rings and magnetic fields those planets possess.

The current mission, the Voyager Interstellar Mission, was planned to explore the outermost edge of our solar system and eventually leave our sun's sphere of influence and enter interstellar space – the space between the stars.

The Golden Record
Both Voyager spacecraft carry recorded messages from Earth on golden phonograph records – 12-inch, gold-plated copper disks. A committee chaired by the late astronomer Carl Sagan selected the contents of the records for NASA. The records are cultural time capsules that the Voyagers carry with them to other star systems. They contain images and natural sounds, spoken greetings in 55 languages and musical selections from different cultures and eras.

Where No Spacecraft Has Gone Before
Voyager 1 has reached a distant point at the edge of our solar system, where the outward motion of solar wind ceases. The event is the latest milestone in Voyager 1's passage through the heliosheath, the outer shell of the sun's sphere of influence, before entering interstellar space. Interstellar space begins at the heliopause, and scientists estimate Voyager 1 will cross this frontier around 2015.

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NASA Invites Public to Journey Toward Interstellar Space

NASA will hold a special NASA Science Update at 10 a.m. PDT (1 p.m. EDT) on Thursday, April 28, to discuss the unprecedented journey of NASA's twin Voyager spacecraft to the edge of our solar system.

The event will be held at NASA Headquarters in Washington and will be broadcast live on NASA Television and streamed at . In addition, the event will be carried live on Ustream, with a live chat box available, at .

After 33 years in space, the spacecraft are still operating and returning data from about 16 billion kilometers (10 billion miles) away from our sun. The Voyagers also carry a collection of images and sounds from Earth as a message to possible life elsewhere in the galaxy.

The participants are:
-- Ed Stone, Voyager project scientist and professor of physics, California Institute of Technology, Pasadena, Calif.
-- Ann Druyan, creative director, Voyager Interstellar Message Project; Carl Sagan's co-author and widow
-- Suzanne Dodd, Voyager project manager, NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
-- Merav Opher, Voyager guest investigator and assistant professor of astronomy, Boston University

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NASA’s STEREO Spacecraft Discovers New Eclipsing Binary Stars

Researchers have discovered 122 new eclipsing binary stars and observed hundreds more variable stars in an innovative survey using NASA's Solar TErrestrial RElations Observatory, or STEREO.

"It's inspiring to learn that STEREO, which was designed to teach us more about the Sun's influence on our solar system, is able to detect other solar systems," said STEREO project scientist Joseph Gurman at NASA's Goddard Space Flight Center in Greenbelt, Md.

Although STEREO is primarily a solar mission, the team realized that the stability of the Heliospheric Imagers (HI) aboard the twin spacecraft could be used to monitor variations in the brightness of stars.

"STEREO's Heliospheric Imagers were designed for stable, accurate measurements to allow us to subtract out the stellar background and see faint coronal mass ejections --- but that same stability allows us to make the incredibly precise measurements necessary to detect such small changes in the brightness of stars,” Gurman remarked.

According to one of the leads in this survey, STEREO's ability to sample continuously for up to 20 days, coupled with repeat viewings from the spacecraft during the year, makes it an invaluable resource for researching variable stars. Observations from the HI cameras are enabling scientists to pin down the periods of known variables with much greater accuracy.

In addition to studying variable stars, the U.K. team announced that HI measurements may be useful for exoplanet and astroseismology research. Very small changes to the brightness of stars can be detected, which could reveal the presence of transiting exoplanets, or trace a star’s internal structure by measuring their seismic activity.

Teams from the Open University, University of Central Lancashire and the Science and Technologies Facilities Council Rutherford Appleton Laboratory carried out the study and their findings were presented at the Royal Astronomical Society’s National Astronomy Meeting in Llandudno, Wales, on April 19.

STEREO is the third mission in NASA's Solar Terrestrial Probes program. The mission, launched in October 2006, has provided a unique and revolutionary view of the Sun-Earth System. The two nearly identical observatories - one ahead of Earth in its orbit, the other trailing behind - have traced the flow of energy and matter from the sun to Earth. STEREO is also key to the fleet of space weather detection satellites by providing more accurate alerts for the arrival time of Earth-directed solar ejections with its unique side-viewing perspective.

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NASA Orbiter Reveals Big Changes in Mars' Atmosphere

NASA's Mars Reconnaissance Orbiter has discovered the total amount of atmosphere on Mars changes dramatically as the tilt of the planet's axis varies. This process can affect the stability of liquid water, if it exists on the Martian surface, and increase the frequency and severity of Martian dust storms.

Researchers using the orbiter's ground-penetrating radar identified a large, buried deposit of frozen carbon dioxide, or dry ice, at the Red Planet's south pole. The scientists suspect that much of this carbon dioxide enters the planet's atmosphere and swells the atmosphere's mass when Mars' tilt increases. The findings are published in this week's issue of the journal Science.

The newly found deposit has a volume similar to Lake Superior's nearly 3,000 cubic miles (about 12,000 cubic kilometers). The deposit holds up to 80 percent as much carbon dioxide as today's Martian atmosphere. Collapse pits caused by dry ice sublimation and other clues suggest the deposit is in a dissipating phase, adding gas to the atmosphere each year. Mars' atmosphere is about 95 percent carbon dioxide, in contrast to Earth's much thicker atmosphere, which is less than .04 percent carbon dioxide.

"We already knew there is a small perennial cap of carbon-dioxide ice on top of the water ice there, but this buried deposit has about 30 times more dry ice than previously estimated," said Roger Phillips of Southwest Research Institute in Boulder, Colo. Phillips is deputy team leader for the Mars Reconnaissance Orbiter's Shallow Radar instrument and lead author of the report.

"We identified the deposit as dry ice by determining the radar signature fit the radio-wave transmission characteristics of frozen carbon dioxide far better than the characteristics of frozen water," said Roberto Seu of Sapienza University of Rome, team leader for the Shallow Radar and a co-author of the new report. Additional evidence came from correlating the deposit to visible sublimation features typical of dry ice.

"When you include this buried deposit, Martian carbon dioxide right now is roughly half frozen and half in the atmosphere, but at other times it can be nearly all frozen or nearly all in the atmosphere," Phillips said.

An occasional increase in the atmosphere would strengthen winds, lofting more dust and leading to more frequent and more intense dust storms. Another result is an expanded area on the planet's surface where liquid water could persist without boiling. Modeling based on known variation in the tilt of Mars' axis suggests several-fold changes in the total mass of the planet's atmosphere can happen on time frames of 100,000 years or less.

The changes in atmospheric density caused by the carbon-dioxide increase also would amplify some effects of the changes caused by the tilt. Researchers plugged the mass of the buried carbon-dioxide deposit into climate models for the period when Mars' tilt and orbital properties maximize the amount of summer sunshine hitting the south pole. They found at such times, global, year-round average air pressure is approximately 75 percent greater than the current level.

"A tilted Mars with a thicker carbon-dioxide atmosphere causes a greenhouse effect that tries to warm the Martian surface, while thicker and longer-lived polar ice caps try to cool it," said co-author Robert Haberle, a planetary scientist at NASA's Ames Research Center in Moffett Field, Calif. "Our simulations show the polar caps cool more than the greenhouse warms. Unlike Earth, which has a thick, moist atmosphere that produces a strong greenhouse effect, Mars' atmosphere is too thin and dry to produce as strong a greenhouse effect as Earth's, even when you double its carbon-dioxide content."

The Shallow Radar, one of the Mars Reconnaissance Orbiter's six instruments, was provided by the Italian Space Agency, and its operations are led by the Department of Information Engineering, Electronics and Telecommunications at Sapienza University of Rome. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter project for NASA's Science Mission Directorate at the agency's headquarters in Washington. Lockheed Martin Space Systems in Denver built the spacecraft.

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NASA's Hubble Celebrates 21st Anniversary with 'Rose' of Galaxies

To celebrate the 21st anniversary of the Hubble Space Telescope's deployment into space, astronomers at the Space Telescope Science Institute in Baltimore, Md., pointed Hubble's eye at an especially photogenic pair of interacting galaxies called Arp 273.

"For 21 years, Hubble has profoundly changed our view of the universe, allowing us to see deep into the past while opening our eyes to the majesty and wonders around us," NASA Administrator Charles Bolden said."I was privileged to pilot space shuttle Discovery as it deployed Hubble. After all this time, new Hubble images still inspire awe and are a testament to the extraordinary work of the many people behind the world's most famous observatory."

Hubble was launched April 24, 1990, aboard Discovery's STS-31 mission. Hubble discoveries revolutionized nearly all areas of current astronomical research from planetary science to cosmology.

"Hubble is America's gift to the world," Sen. Barbara Mikulski of Maryland said. "Its jaw-dropping images have rewritten the textbooks and inspired generations of schoolchildren to study math and science. It has been documenting the history of our universe for 21 years. Thanks to the daring of our brave astronauts, a successful servicing mission in 2009 gave Hubble new life. I look forward to Hubble's amazing images and inspiring discoveries for years to come."

The newly released Hubble image shows a large spiral galaxy, known as UGC 1810, with a disk that is distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy below it, known as UGC 1813. A swath of blue jewel-like points across the top is the combined light from clusters of intensely bright and hot young blue stars. These massive stars glow fiercely in ultraviolet light.

The smaller, nearly edge-on companion shows distinct signs of intense star formation at its nucleus, perhaps triggered by the encounter with the companion galaxy.

Arp 273 lies in the constellation Andromeda and is roughly 300 million light-years away from Earth. The image shows a tenuous tidal bridge of material between the two galaxies that are separated from each other by tens of thousands of light-years.

A series of uncommon spiral patterns in the large galaxy are a tell-tale sign of interaction. The large, outer arm appears partially as a ring, a feature seen when interacting galaxies actually pass through one another. This suggests the smaller companion dived deep, but off-center, through UGC 1810. The inner set of spiral arms is highly warped out of the plane, with one of the arms going behind the bulge and coming back out the other side. How these two spiral patterns connect is not precisely known.

The larger galaxy in the UGC 1810 - UGC 1813 pair has a mass about five times that of the smaller galaxy. In unequal pairs such as this, the relatively rapid passage of a companion galaxy produces the lopsided or asymmetric structure in the main spiral. Also in such encounters, the starburst activity typically begins in the minor galaxies earlier than in the major galaxies. These effects could be because the smaller galaxies have consumed less of the gas present in their nuclei, from which new stars are born.

The interaction was imaged on Dec. 17, 2010, with Hubble's Wide Field Camera 3 (WFC3). The picture is a composite of data taken with three separate filters on WFC3 that allow a broad range of wavelengths covering the ultraviolet, blue, and red portions of the spectrum.

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

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JPL Director Charles Elachi Receives Multiple Honors

The director of NASA's Jet Propulsion Laboratory, Charles Elachi, is receiving multiple awards and honors this year in the United States and overseas.

"I'm extremely pleased to receive all these honors, which reflect the groundbreaking research and projects I've had the opportunity to work on with my colleagues at Caltech, JPL and NASA through the years," Elachi said.

This week, Elachi accepted the 2011 General James E. Hill Lifetime Space Achievement Award from the Space Foundation. The award was presented at the National Space Symposium in Colorado Springs, Colo.

The award, named for the Space Foundation's former chairman, Gen. James E. Hill, USAF (retired), recognizes "outstanding individuals who have distinguished themselves through lifetime contributions to the welfare or betterment of humankind through exploration, development and use of space, or through use of space technology, information, themes or resources in academic, cultural, industrial or other pursuits of broad benefit to humanity."

On March 5, Elachi was presented with an honorary doctor of science degree by Occidental College in Los Angeles during its 40th annual President's Circle Dinner at JPL. Also in March, he received the American Astronautical Society's 2011 Carl Sagan Memorial Award at the organization's symposium in Greenbelt, Md. The award, presented in cooperation with the Planetary Society, is given to individuals who demonstrate leadership in research or policies advancing exploration of the cosmos.

In addition to the trio of awards he has accepted in the United States this year, Elachi is receiving two international honors.

He is being inducted into the French Legion, known as the Chevalier de la Legion d'Honneur. Although Elachi is a native of Lebanon, and the award is traditionally restricted to natives of France, the honor has been bestowed on foreign nationals "who have served France or the ideals it upholds." Being honored at age 16 as Lebanon's top science student enabled Elachi to attend the college of his choice, France's University of Grenoble, where he earned a bachelor's degree in physics in 1968. That same year, he received an engineering degree from the Polytechnic Institute in Grenoble, where he graduated first in the class.

"I'm very honored to be recognized with such a prestigious award," said Elachi, who will formally accept the honor for his life's work at a ceremony in the near future. "The years I spent in France, at the University of Grenoble and the Polytechnic Institute in Grenoble, were an important part of my life and helped pave the way for my career."

After studying in France, Elachi moved to Pasadena, where he received a master's (1969) and Ph.D. (1971) in electrical sciences from the California Institute of Technology. He also earned a master's degree (1983) in geology from UCLA and an MBA (1979) from USC.

Elachi noted that throughout his career, his links to France have continued through his research.

He joined JPL in 1970 as a researcher on various Earth and planetary missions. Elachi has been serving as JPL director since May 2001, and the decade since then has included such successful NASA space missions as the Mars Exploration Rovers Spirit and Opportunity, the Phoenix Mars Lander, Stardust, Spitzer, Kepler, and such Earth-orbiting satellites as Grace and Topex/Poseidon-Jason.

"Over the last three decades, JPL and the French Space Agency, working together, have revolutionized the field of oceanography by developing the capability to observe and monitor ocean currents on a global basis from space," Elachi said.

In addition to serving as JPL director, Elachi is vice president of Caltech, and an electrical engineering and planetary science professor. Caltech manages JPL for NASA.

Elachi has recently been listed in the top 10 on the Arabian Business Magazine "Power 500" list of the world's most influential people of Arab descent. The award looks at the influence of people from the Middle East in every sector: from the business world, media, entertainment, sports, science, arts and academia. Elachi is described as "one person who has driven mankind's thirst for knowledge about the other planets in our solar system."

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Clouds, Clouds, Burning Bright

High up in the sky near the poles some 50 miles above the ground, silvery blue clouds sometimes appear, shining brightly in the night. First noticed in 1885, these clouds are known as noctilucent, or "night shining," clouds. Their discovery spawned over a century of research into what conditions causes them to form and vary – questions that still tantalize scientists to this day. Since 2007, a NASA mission called Aeronomy of Ice in the Mesosphere (AIM) has shown that the cloud formation is changing year to year, a process they believe is intimately tied to the weather and climate of the whole globe.

"The formation of the clouds requires both water and incredibly low temperatures," says Charles Jackman, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., who is NASA's project scientist for AIM. "The temperatures turn out to be one of the prime driving factors for when the clouds appear."

So the appearance of the noctilucent clouds, also known as polar mesospheric clouds or PMCs since they occur in a layer of the atmosphere called the mesosphere, can provide information about the temperature and other characteristics of the atmosphere. This in turn, helps researchers understand more about Earth's low altitude weather systems, and they've discovered that events in one hemisphere can have a sizable effect in another.

Since these mysterious clouds were first spotted, researchers have learned much about them. They light up because they're so high that they reflect sunlight from over the horizon. They are formed of ice water crystals most likely created on meteoric dust. And they are exclusively a summertime phenomenon.

"The question people usually ask is why do clouds which require such cold temperatures form in the summer?" says James Russell, an atmospheric scientist at Hampton University in Hampton, Va., who is the Principal Investigator for AIM. "It's because of the dynamics of the atmosphere. You actually get the coldest temperatures of the year near the poles in summer at that height in the mesosphere."

As summer warmth heats up air near the ground, the air rises. As it rises, it also expands since atmospheric pressure decreases with height. Scientists have long known that such expansion cools things down – just think of how the spray out of an aerosol can feels cold – and this, coupled with dynamics in the atmosphere that drives the cold air even higher, brings temperatures in the mesosphere down past a freezing -210º F (-134 ºC).

In the Northern hemisphere, the mesosphere reaches these temperatures consistently by the middle of May. Since AIM has been collecting data, the onset of the Northern season has never varied by more than a week or so. But the southern hemisphere turns out to be highly variable. Indeed, the 2010 season started nearly a month later than the 2009 season.

Atmospheric scientist Bodil Karlsson, a member of the AIM team, has been analyzing why the start of the southern noctilucent cloud season can vary so dramatically. Karlsson is a researcher at Stockholm University in Sweden, though until recently she worked as a post-doctoral researcher at the University of Colorado. A change in when some pretty clouds show up may not seem like much all by itself, but it's a tool for mapping the goings-on in the atmosphere, says Karlsson.

"Since the clouds are so sensitive to the atmospheric temperatures," says Karlsson. "They can act as a proxy for information about the wind circulation that causes these temperatures. They can tell us that the circulation exists first of all, and tell us something about the strength of the circulation."

She says the onset of the clouds is timed to something called the southern stratospheric vortex – a winter wind pattern that circles above the pole. In 2010, that vortex lingered well into the southern summer season, keeping the lower air cold and interfering with cloud formation. This part of the equation is fairly straightforward and Karlsson has recently submitted a paper on the subject to the Journal of Geophysical Research. But this is not yet the complete answer to what drives the appearance of these brightly lit clouds.

AIM researchers also believe there is a connection between seemingly disparate atmospheric patterns in the north and south. The upwelling of polar air each summer that contributes to noctilucent cloud formation is part of a larger circulation loop that travels between the two poles. So wind activity some 13,000 miles (20,920 km) away in the northern hemisphere appears to be influencing the southern circulation.

The first hints that wind in the north and south poles were coupled came in 2002 and 2003 when researchers noticed that despite a very calm lower weather system near the southern poles in the summer, the higher altitudes showed variability. Something else must be driving that change.

Now, AIM's detailed images of the clouds have enabled researchers to look at even day-to-day variability. They've spotted a 3 to10 day time lag between low-lying weather events in the north – an area that, since it is fairly mountainous, is prone to more complex wind patterns – and weather events in the mesosphere in the south. On the flip side, the lower atmosphere at the southern poles has little variability, and so the upper atmosphere where the clouds form at the northern poles stays fairly constant. Thus, there's a consistent start to the cloud season each year.

"The real importance of all of that," says Hampton's Russell, "is not only that events down where we live can affect the clouds 50 miles (80 km) above, but that the total atmosphere from one pole to the next is rather tightly connected."

Hammering out the exact mechanisms of that connection will, of course, take more analysis. The noctilucent cloud season will also surely be affected by the change in heat output from the sun during the upcoming solar maximum. Researchers hope to use the clouds to understand how the sun's cycle affects the Earth's atmosphere and the interaction between natural- and humankind-caused changes.

"These are the highest clouds in Earth's atmosphere, formed in the coldest place in Earth's atmosphere," says Goddard's Jackman. "Although the clouds occur only in the polar summer, they help us to understand more about the whole globe."

AIM is a NASA-funded Small Explorers (SMEX) mission. NASA Goddard manages the program for the agency's Science Mission Directorate at NASA headquarters in Washington. The mission is led by the Principal Investigator from the Center for Atmospheric Sciences at Hampton University in Virginia. The Laboratory for Atmospheric and Space Physics (LASP), University of Colorado, Boulder, and the Space Dynamics Laboratory, Utah State University, built the instruments. LASP also manages the mission and controls the satellite.

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Two Kinds of Webb Telescope Mirrors Arrive at NASA Goddard

It takes two unique types of mirrors working together to see farther back in time and space than ever before, and engineers at NASA's Goddard Space Flight Center have just received one of each type. Primary and Secondary Mirror Engineering Design Units (EDUs) have recently arrived at NASA's Goddard Space Flight Center in Greenbelt, Md. from Northrop Grumman Aerospace Systems in Redondo Beach, Calif. and are undergoing examination and testing. When used on the James Webb Space Telescope those two types of mirrors will allow scientists to make those observations.

"The Primary mirror EDU will be used next year to check out optical test equipment developed by Goddard and slated to be used to test the full Flight Primary mirror," said Lee Feinberg, the Optical Telescope Element Manager for the Webb telescope at NASA Goddard. "Following that, the primary and secondary EDU's will actually be assembled onto the Pathfinder telescope. The Pathfinder telescope includes two primary mirror segments (one being the Primary EDU) and the Secondary EDU and allows us to check out all of the assembly and test procedures (that occur both at Goddard and testing at Johnson Space Center, Houston, Texas) well in advance of the flight telescope assembly and test."

The primary mirror is actually composed of 18 smaller hexagonal mirrors that are assembled together into what appears to be a giant hexagon that sits atop the Webb telescope's sunshield. Webb Telescope's scientists and engineers determined that a primary mirror measuring 6.5 meters (21 feet 4 inches) across is what was needed to measure the light from these distant galaxies. Each of these mirrors is constructed from beryllium, a light and strong metal. Each of the 18 mirror segments weighs approximately 20 kilograms (46 pounds).

Why are the mirrors hexagonal shaped? Because a hexagon allows a segmented mirror to fit together without gaps. When Webb's primary mirror is focused on a distant star for example, that image will appear in all 18 mirror segments. To focus on the star and get one image, the mirror segments can then be tilted to align the 18 separate images into a single image.

Although there are 18 segments, there are three different optical prescriptions for the 18 segments: six segments of each prescription. The segment received is the first of the "A" prescription segments for which a total of 7 will be made - 6 flight and 1 spare. A prescription is similar to an eyeglass prescription and specifies a unique mirror curvature. Like eyeglasses, mirrors with the same prescription are interchangeable.

The primary mirror EDU that arrived at Goddard is also a flight spare. That means it can be used on the actual telescope. In fact, it could even be put on the telescope now if needed.

The primary mirror segment has already been cleaned and coated. Ball Aerospace & Technologies cleaned the mirror segment and Quantum Coating, Inc., in Moorestown, N.J., coated it. Ball Aerospace then took the mirror segment back, reassembled it with mounts and actuators and conducted final vibration testing.

Afterward, the mirror segment went back to the X-ray and Cryogenic Facility (XRCF) in Huntsville, Ala., where Ball performed final cryogenic acceptance testing on the segment before it came to NASA Goddard.

The secondary mirror on the Webb telescope will direct the light from the primary mirror to where it can be collected by the Webb's instruments. The secondary mirror is connected to "arms" that position it in front of the 18 primary mirror segments. It will focus all of the light from the 18 primary mirrors.

The secondary EDU at Goddard is not coated but can be, so it can be a flight spare once coated.

Eventually, the final flight mirrors will all come to NASA Goddard and be assembled on the telescope and the instrument module. Then, as a complete unit it will undergo acoustic and vibration testing at Goddard.

The James Webb Space Telescope is the world’s next-generation space observatory and successor to the Hubble Space Telescope. The most powerful space telescope ever built, Webb will observe the most distant objects in the universe, provide images of the very first galaxies ever formed and see unexplored planets around distant stars. The Webb Telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

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The Watched Pot and Fast CMEs

If you've ever stood in front of a hot stove, watching a pot of water and waiting impatiently for it to boil, you know what it feels like to be a solar physicist.

Back in 2008, the solar cycle plunged into the deepest minimum in nearly a century. Sunspots all but vanished, solar flares subsided, and the sun was eerily quiet.

"Ever since, we've been waiting for solar activity to pick up," says Richard Fisher, head of the Heliophysics Division at NASA Headquarters in Washington DC. "It's been three long years."

Quiet spells on the sun are nothing new. They come along every 11 years or so—it's a natural part of the solar cycle. This particular solar minimum, however, was lasting longer than usual, prompting some researchers to wonder if it would ever end.

News flash: The pot is starting to boil. "Finally," says Fisher, "we are beginning to see some action."

As 2011 unfolds, sunspots have returned and they are crackling with activity. On February 15th and again on March 9th, Earth orbiting satellites detected a pair of "X-class" solar flares--the most powerful kind of x-ray flare. The last such eruption occurred back in December 2006.

Another eruption on March 7th hurled a billion-ton cloud of plasma away from the sun at five million mph (2200 km/s). The rapidly expanding cloud wasn't aimed directly at Earth, but it did deliver a glancing blow to our planet's magnetic field. The off-center impact on March 10th was enough to send Northern Lights spilling over the Canadian border into US states such as Wisconsin, Minnesota, and Michigan.

"That was the fastest coronal mass ejection in almost six years," says Angelos Vourlidas of the Naval Research Lab in Washington DC. "It reminds me of a similar series of events back in Nov. 1997 that kicked off Solar Cycle 23, the solar cycle before this one."

"To me," says Vourlidas, "this marks the beginning of Solar Cycle 24."

The slow build-up to this moment is more than just "the watched pot failing to boil," says Ron Turner, a space weather analyst at Analytic Services, Inc. "It really has been historically slow."

There have been 24 numbered solar cycles since researchers started keeping track of them in the mid-18th century. In an article just accepted for publication by the Space Weather Journal, Turner shows that, in all that time, only four cycles have started more slowly than this one. "Three of them were in the Dalton Minimum, a period of depressed solar activity in the early 19th century. The fourth was Cycle #1 itself, around 1755, also a relatively low solar cycle," he says.

In his study, Turner used sunspots as the key metric of solar activity. Folding in the recent spate of sunspots does not substantially alter his conclusion: "Solar Cycle 24 is a slow starter," he says.

Better late than never.

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Do Cosmic Strings of Gas Come From Sonic Booms?

The Herschel Space Observatory has revealed that clouds between stars contain networks of tangled gaseous filaments. Intriguingly, each filament is approximately the same width, hinting that they may result from interstellar sonic booms throughout our Milky Way galaxy.

The filaments are huge, stretching for tens of light years through space, and Herschel has shown that newborn stars are often found in the densest parts of them. One filament imaged by Herschel in the Aquila region contains a cluster of about 100 infant stars.

Such filaments in interstellar clouds have been glimpsed before by other infrared satellites, but they have never been seen clearly enough to have their widths measured. Now, Herschel has shown that, regardless of the length or density of a filament, the width is always roughly the same.

The team suggests that as sonic booms from exploding stars travel through the clouds, they lose energy and, where they finally dissipate, they leave these filaments of compressed material.

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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NASA Telescopes Help Discover Surprisingly Young Galaxy

Astronomers have uncovered one of the youngest galaxies in the distant universe, with stars that formed 13.5 billion years ago, a mere 200 million years after the Big Bang. The finding addresses questions about when the first galaxies arose, and how the early universe evolved.

NASA's Hubble Space Telescope was the first to spot the newfound galaxy. Detailed observations from the W.M. Keck Observatory on Mauna Kea in Hawaii revealed the observed light dates to when the universe was only 950 million years old; the universe formed about 13.7 billion years ago.

Infrared data from both Hubble and the post-coolant, or "warm," phase of NASA's Spitzer Space Telescope mission revealed the galaxy's stars are quite mature, which means they must have formed when the universe was just a toddler.

"This challenges theories of how soon galaxies formed in the first years of the universe," said Johan Richard of the Centre de Recherche Astronomique de Lyon, Université Lyon 1 in France, lead author of a new study accepted for publication in the Monthly Notices of the Royal Astronomical Society. "It could even help solve the mystery of how the hydrogen fog that filled the early universe was cleared."

This galaxy is not the most distant ever observed, but it is one of the youngest to be observed with such clarity. Normally, galaxies like this one are extremely faint and difficult to study, but, in this case, nature has provided the astronomers with a cosmic magnifying glass. The galaxy's image is being magnified by the gravity of a massive cluster of galaxies parked in front of it, making it appear 11 times brighter. This phenomenon is called gravitational lensing.

"Without this big lens in space, we could not study galaxies this faint with currently available observing facilities," said co-author Eiichi Egami of the University of Arizona in Tucson. "Thanks to nature, we have this great opportunity to see our universe as it was eons ago."

The findings may help explain how the early universe became "reionized." At some point in our universe's early history, it transitioned from the so-called dark ages to a period of light, as the first stars and galaxies began to ignite. This starlight ionized neutral hydrogen atoms floating around in space, giving them a charge. Ultraviolet light could then travel unimpeded through what had been an obscuring fog.

The discovery of a galaxy possessing stars that formed only 200 million years after the big bang helps astronomers probe this cosmic reionization epoch. When this galaxy was developing, its hot, young stars would have ionized vast amounts of the neutral hydrogen gas in intergalactic space. A population of similar galaxies probably also contributed to this reionization, but they are too faint to see without the magnifying effects of gravitational lensing.

NASA's James Webb Space Telescope (JWST), scheduled to launch later this decade, will be able to see these faint galaxies lacking magnification. A successor to Hubble and Spitzer, JWST will see infrared light from the missing population of early galaxies. As a result, the mission will reveal some of our universe's best-kept secrets.

"Seeing a galaxy as it appeared near the beginning of the universe is an awe-inspiring feat enabled by innovative technology and the fortuitous effect of gravitational lensing," said Jon Morse, NASA's Astrophysics Division director at the agency's headquarters in Washington. "Observations like this open a window across space and time, but more importantly, they inspire future work to one day peer at the stars that lit up the universe following the big bang."

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena.

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Mars Rover's 'Gagarin' Moment Applauded Exploration

A flat, light-toned rock on Mars visited by NASA's Mars Exploration Rover in 2005 informally bears the name of the first human in space, Yuri Gagarin, who rode into orbit in the Soviet Union's Vostok-1 spacecraft on April 12, 1961.

The team using Opportunity to explore the Meridiani Planum region of Mars since 2004 chose "Gagarin" for what they would call the rock that the rover examined beside "Vostok" crater. A target for close-up examination on Gagarin is called "Yuri."

To commemorate Gagarin's flight, a color image of the rock on Mars has been posted, here. The image combines frames taken through three different filters by Opportunity's panoramic camera.

Early accomplishments in the Space Age inspired many of the researchers exploring other planets robotically today, who hope their work can, in turn, help inspire the next generation.

"The 50th anniversary of mankind's first fledgling foray into the cosmos should serve as an important reminder of the spirit of adventure and exploration that has propelled mankind throughout history," said Mars rover science team member James Rice of NASA Goddard Space Flight Center, Greenbelt, Md. "We are a species of explorers; it is encoded into our very DNA."

Rice continued, "Half a century ago Yuri Gagarin was lofted into a totally unknown, remote and hostile environment and in doing so opened up a new limitless frontier of possibilities for mankind. A mere 23 days later another brave human, Alan Shepard, climbed aboard a rocket and ventured into the starry abyss. Their courage and vision continue to inspire and lead us into the unknown. Hopefully, one day in the not too distant future it will lead humanity on a voyage to Mars."

Opportunity and its twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued in years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit has not communicated with Earth since March 2010. Opportunity remains active. This month, it has passed both the 27-kilometer and 17-mile marks in its total driving distance on Mars.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.

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WISE Mission Spots 'Horseshoe' Asteroid

An asteroid recently discovered by NASA's Wide-field Infrared Survey Explorer (WISE) may be a bit of an oddball. Most near-Earth asteroids -- NEAs for short -- have eccentric, or egg-shaped, orbits that take the asteroids right through the inner solar system. The new object, designated 2010 SO16, is different. Its orbit is almost circular such that it cannot come close to any other planet in the solar system except Earth.

However, even though the asteroid rides around with Earth, it never gets that close.

"It keeps well away from Earth," said Apostolos "Tolis" Christou, who, together with David Asher of the Armagh Observatory in Northern Ireland, analyzed the orbit of the body after it was discovered in infrared images taken by WISE. "So well, in fact, that it has likely been in this orbit for several hundred thousand years, never coming closer to our planet than 50 times the distance to the moon."

The asteroid is one of a few that trace out a horseshoe shape relative to Earth. As the asteroid approaches Earth, the planet's gravity causes the object to shift back into a larger orbit that takes longer to go around the sun than Earth. Alternately, as Earth catches up with the asteroid, the planet's gravity causes it to fall into a closer orbit that takes less time to go around the sun than Earth. The asteroid therefore never completely passes our planet. This slingshot-like effect results in a horseshoe-shaped path as seen from Earth, in which 2010 SO16 takes 175 years to get from one end of the horseshoe to the other.

"The origins of this object could prove to be very interesting," said Amy Mainzer of NASA's Jet Propulsion Laboratory, Pasadena, Calif., the principal investigator of NEOWISE, which is the asteroid- and comet-hunting portion of the WISE survey mission. "We are really excited that the astronomy community is already finding treasures in the NEOWISE data that have been released so far."

NEOWISE finished its one complete sweep of the solar system in early February of this year. Data on the orbits of asteroids and comets detected by the project, including near-Earth objects, are catalogued at the NASA-funded International Astronomical Union's Minor Planet Center, at the Smithsonian Astrophysical Observatory in Cambridge, Mass.

A full story from the Armagh Observatory, including animations, is online at

JPL manages and operates the Wide-field Infrared Survey Explorer 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 the 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 Telescopes Join Forces to Observe Unprecedented Explosion

NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location.

Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours.

Although research is ongoing, astronomers say that the unusual blast likely arose when a star wandered too close to its galaxy's central black hole. Intense tidal forces tore the star apart, and the infalling gas continues to stream toward the hole. According to this model, the spinning black hole formed an outflowing jet along its rotational axis. A powerful blast of X- and gamma rays is seen if this jet is pointed in our direction.

On March 28, Swift's Burst Alert Telescope discovered the source in the constellation Draco when it erupted with the first in a series of powerful X-ray blasts. The satellite determined a position for the explosion, now cataloged as gamma-ray burst (GRB) 110328A, and informed astronomers worldwide.

As dozens of telescopes turned to study the spot, astronomers quickly noticed that a small, distant galaxy appeared very near the Swift position. A deep image taken by Hubble on April 4 pinpoints the source of the explosion at the center of this galaxy, which lies 3.8 billion light-years away.

That same day, astronomers used NASA's Chandra X-ray Observatory to make a four-hour-long exposure of the puzzling source. The image, which locates the object 10 times more precisely than Swift can, shows that it lies at the center of the galaxy Hubble imaged.

"We know of objects in our own galaxy that can produce repeated bursts, but they are thousands to millions of times less powerful than the bursts we are seeing now. This is truly extraordinary," said Andrew Fruchter at the Space Telescope Science Institute in Baltimore.

"We have been eagerly awaiting the Hubble observation," said Neil Gehrels, the lead scientist for Swift at NASA's Goddard Space Flight Center in Greenbelt, Md. "The fact that the explosion occurred in the center of a galaxy tells us it is most likely associated with a massive black hole. This solves a key question about the mysterious event."

Most galaxies, including our own, contain central black holes with millions of times the sun's mass; those in the largest galaxies can be a thousand times larger. The disrupted star probably succumbed to a black hole less massive than the Milky Way's, which has a mass four million times that of our sun

Astronomers previously have detected stars disrupted by supermassive black holes, but none have shown the X-ray brightness and variability seen in GRB 110328A. The source has repeatedly flared. Since April 3, for example, it has brightened by more than five times.

Scientists think that the X-rays may be coming from matter moving near the speed of light in a particle jet that forms as the star's gas falls toward the black hole.

"The best explanation at the moment is that we happen to be looking down the barrel of this jet," said Andrew Levan at the University of Warwick in the United Kingdom, who led the Chandra observations. "When we look straight down these jets, a brightness boost lets us view details we might otherwise miss."

This brightness increase, which is called relativistic beaming, occurs when matter moving close to the speed of light is viewed nearly head on.

Astronomers plan additional Hubble observations to see if the galaxy's core changes brightness.

NASA Goddard manages Swift, and Hubble, and NASA's Marshall Space Flight Center in Huntsville, Ala., manages Chandra. The Hubble Space Telescope was built and is operated in partnership with the European Space Agency. Science operations for all three missions include contributions from many national and international partners.

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NASA's Aquarius: The Water Bearer Flies Soon

With more than a few stamps on its passport, NASA's Aquarius instrument on the Argentinian Satélite de Aplicaciones Científicas (SAC)-D spacecraft will soon embark on its space mission to "taste" Earth's salty ocean.

After a journey of development and assembly through NASA facilities, a technology center in Bariloche, Argentina, and testing chambers in Brazil, the Aquarius instrument, set to measure the ocean's surface salinity, recently made the trip from São José dos Campos, Brazil, to California's Vandenberg Air Force Base for final integration and testing before its scheduled launch on June 9.

Aquarius will map the concentration of dissolved salt at the ocean's surface, information that scientists will use to study the ocean's role in the global water cycle and how this is linked to ocean currents and climate. Sea surface temperature has been monitored by satellites for decades, but it is both temperature and salinity that determine the density of the surface waters of the ocean. Aquarius will provide fundamentally new ocean surface salinity data to give scientists a better understanding of the density-driven circulation; how it is tied to changes in rainfall and evaporation, or the melting and freezing of ice; and its effect on climate variability.

"The ocean is essentially Earth's thermostat. It stores most of the heat, and what we need to understand is how do changes in salinity affect the 3-D circulation of the ocean," said Gene Feldman, Aquarius Ground System and Mission Operations Manager at NASA's Goddard Space Flight Center, Greenbelt, Md.

The development of the Aquarius mission began more than 10 years ago as a joint effort between Goddard and NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. In 2008, Goddard engineers completed the Aquarius microwave radiometer instrument, which is the key component for measuring salinity from space.

"The radiometer is the most accurate and stable radiometer built for sensing of Earth from space. It's a one-of-a-kind instrument," said Shannon Rodriguez-Sanabria, a microwave communications specialist at Goddard.

JPL built Aquarius' scatterometer instrument, a microwave radar sensor that scans the ocean's surface to measure the effect wind speed has on the radiometer measurements. The radiometer and scatterometer instruments, along with an 8.25-by-10-foot elliptical antenna reflector and many other systems, have been integrated together at JPL to form the complete Aquarius instrument. A number of other instruments aboard the SAC-D spacecraft are contributions from Argentina, France, Canada and Italy.

In June 2009, Aquarius was flown via a U.S. Air Force cargo jet to San Carlos de Bariloche, Argentina, a destination known for its natural scenery of blue lakes and verdant mountains, to be integrated with Argentina's SAC-D spacecraft. A year later, the fully assembled spacecraft and all the instruments now referred to as the "Aquarius/SAC-D Observatory" were shipped to Brazil. There, engineers began a nine-month campaign of alignment, electro-magnetic, vibration, and thermal vacuum testing to ensure it will survive the rigors of launch and orbiting in space.

JPL will manage the Aquarius mission through Aquarius' commissioning phase, scheduled to last 45 days after launch. Goddard will then manage the Aquarius instrument operations during the mission. Argentina's Comisión Nacional de Actividades Espaciales (CONAE) will operate the spacecraft and download all of the data collected by Aquarius several times per day. Goddard is responsible for producing the Aquarius science data products. JPL will manage the data archive and distribution to scientists worldwide.

Aquarius will collect data continuously as it flies in a near-polar orbit and circles Earth 14 to 15 times each day. The field of view of the instrument is 390 kilometers (242 miles) wide, and will provide a global map every seven days. The data will be compiled to generate more accurate monthly averages during the mission, which is designed to last a minimum of three years.

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The Soyuz TMA-21 launched from the Baikonur Cosmodrome in Kazakhstan on Tuesday, April 5, 2011, carrying Expedition 27 Soyuz Commander Alexander Samokutyaev, NASA Flight Engineer Ron Garan and Russian Flight Engineer Andrey Borisenko to the International Space Station. The Soyuz, which has been dubbed "Gagarin", is launching one week shy of the 50th anniversary of the launch of Yuri Gagarin from the same launch pad in Baikonur on April 12, 1961 to become the first human to fly in space.

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NASA's Spitzer Discovers Time-Delayed Jets

Astronomers have discovered that two symmetrical jets shooting away from opposite sides of a blossoming star are experiencing a time delay: knots of gas and dust from one jet blast off four-and-a-half years later than identical knots from the other jet.

The finding, which required the infrared vision of NASA's Spitzer Space Telescope, is helping astronomers understand how jets are produced around forming stars, including those resembling our sun when it was young.

"More studies are needed to determine if other jets have time delays," said Alberto Noriega-Crespo of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena, who is a co-author of the new study to be published in the April 1 issue of Astrophysical Journal Letters. "Now we know that in at least one case, there appears to be a delay, which tells us that some sort of communication may be going on between the jets that takes time to occur."

Jets are an active phase in a young star's life. A star begins as a collapsing, roundish cloud of gas and dust. By ejecting supersonic jets of gas, the cloud slows down its spinning. As material falls onto the growing star, it develops a surrounding disk of swirling material and twin jets that shoot off from above and below the disk, like a spinning top.

Once the star ignites and shines with starlight, the jets will die off and the disk will thin out. Ultimately, planets may clump together out of material left in the spinning disk.

The discovery of the time delay, in the jets called Herbig-Haro 34, has also led the astronomers to narrow in on the size of the zone from which the jets originate. The new Spitzer observations limit this zone to a circle around the young star with a radius of 3 astronomical units. An astronomical unit is the distance between our sun and Earth. This is about 10 times smaller than previous estimates.

"Where we stand today on Earth was perhaps once a very violent place where high-velocity gas and dust were ejected from the disk circling around our very young sun," said Alex Raga of the Universidad Nacional Autónoma de México, the first author of the paper. "If so, the formation of planets like Earth depends on how and when this phenomenon ended. Essentially, every star like our own sun has gone through a similar cloud-disk-jets formation process."

One of the jets in Herbig-Haro 34 had been studied extensively for years, but the other remained hidden behind a dark cloud. Spitzer's sensitive infrared vision was able to pierce this cloud, revealing the obscured jet in greater detail than ever before. Spitzer images show that the newfound jet is perfectly symmetrical to its twin, with identical knots of ejected material.

This symmetry turned out to be key to the discovery of the jets' time delay. By measuring the exact distances from the knots to the star, the astronomy team was able to figure out that, for every knot of material punched out by one jet, a similar knot is shot out in the opposite direction 4.5 years later. This calculation also depended on the speed of the jets, which was known from previous studies by NASA's Hubble Space Telescope. Other symmetrical jets similar to Herbig-Haro 34 have been observed closely before, but it is not clear if they are also experiencing time delays.

The astronomers say that some kind of communication is going on between the Herbig-Haro 34 jets, likely carried by sound waves. Knowing the length of the time delay and the speed of sound allowed them to calculate the maximum size of the jet-making zone.

The astronomy team is currently analyzing other jets imaged by Spitzer, looking for more evidence of time delays.

The Spitzer observations were made before it used up its liquid coolant in May 2009 and began its warm mission.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington.

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Pretty in Pink

Inside the Plasma Spray-Physical Vapor Deposition, or PS-PVD, ceramic powder is introduced into the plasma flame, which vaporizes it and then condenses it to form the ceramic coating.

The PS-PVD rig at NASA's Glenn Research Center uses new technology to create super thin ceramic coatings, which are being developed to protect high efficiency engines. The coatings created in the PS-PVD rig are thinner and more complex than those previously available.

The PS-PVD rig uses a system of vacuum pumps and a blower to remove air from the chamber, reducing the pressure inside to fraction of normal atmospheric pressure. The plasma flame is extremely hot and reaches 10,000 degrees Celsius. Ceramic powder is introduced from the torch into the plasma flame. The plasma vaporizes the ceramic powder, which then condenses 5 feet away from the torch onto the component to form the ceramic coating.

Plasma--not a gas, liquid or solid--is the fourth state of matter and often behaves like a gas, except that it conducts electricity and is affected by magnetic fields. On an astronomical scale, plasma is common. The sun is composed of plasma, fire is plasma, fluorescent and neon lights contain plasma. NASA’s PS-PVD rig is one of only two such facilities in the country and one of four in the world.

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NASA’s Kepler Mission Helps Reveal the Inner Secrets of Giant Stars for the First Time

University of Sydney astrophysicists are behind a major breakthrough in the study of the senior citizens of our galaxy: stars known as Red Giants. Using high precision brightness measurements taken by the Kepler spacecraft, scientists have been able to distinguish profound differences inside the cores of stars that otherwise look the same on the surface.

The discovery, published in the latest edition of the journal Nature and made possible by observations using NASA's powerful Kepler space telescope, is shedding new light on the evolution of stars, including our own sun.

The paper's lead author, the University of Sydney's Professor Tim Bedding, explains, "Red giants are evolved stars that have exhausted the supply of hydrogen in their cores that powers nuclear fusion, and instead burn hydrogen in a surrounding shell. Towards the end of their lives, red giants begin burning the helium in their cores."

The Kepler space telescope has allowed Professor Bedding and colleagues to continuously study starlight from hundreds of red giants at an unprecedented level of precision for nearly a year, opening up a window into the stars' cores.

"The changes in brightness at a star's surface is a result of turbulent motions inside that cause continuous star-quakes, creating sound waves that travel down through the interior and back to the surface," Professor Bedding said.

"Under the right conditions, these waves interact with other waves trapped inside the star's helium core. It is these 'mixed' oscillation modes that are the key to understanding a star's particular life stage. By carefully measuring very subtle features of the oscillations in a star's brightness, we can see that some stars have run out of hydrogen in the center and are now burning helium, and are therefore at a later stage of life."

Astronomer Travis Metcalfe of the US National Center for Atmospheric Research, in a companion piece in the same Nature issue which highlights the discovery's significance, compares red giants to Hollywood stars, whose age is not always obvious from the surface. "During certain phases in a star's life, its size and brightness are remarkably constant, even while profound transformations are taking place deep inside."

Professor Bedding and his colleagues work in an expanding field called asteroseismology. "In the same way that geologists use earthquakes to explore Earth's interior, we use star quakes to explore the internal structure of stars," he explained.

Professor Bedding said: "We are very excited about the results. We had some idea from theoretical models that these subtle oscillation patterns would be there, but this confirms our models. It allows us to tell red giants apart, and we will be able to compare the fraction of stars that are at the different stages of evolution in a way that we couldn't before."

Daniel Huber, a PhD student working with Professor Bedding, added: "This shows how wonderful the Kepler satellite really is. The main aim of the telescope was to find Earth-sized planets that could be habitable, but it has also provided us with a great opportunity to improve our understanding of stars."

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