Sunday, October 24, 2010

Pinwheel of Star Birth

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Though the universe is chock full of spiral-shaped galaxies, no two look exactly the same. This face-on spiral galaxy, called NGC 3982, is striking for its rich tapestry of star birth, along with its winding arms. The arms are lined with pink star-forming regions of glowing hydrogen, newborn blue star clusters, and obscuring dust lanes that provide the raw material for future generations of stars. The bright nucleus is home to an older population of stars, which grow ever more densely packed toward the center.

NGC 3982 is located about 68 million light-years away in the constellation Ursa Major. The galaxy spans about 30,000 light-years, one-third of the size of our Milky Way galaxy. This color image is composed of exposures taken by the Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2), the Advanced Camera for Surveys (ACS), and the Wide Field Camera 3 (WFC3). The observations were taken between March 2000 and August 2009. The rich color range comes from the fact that the galaxy was photographed invisible and near-infrared light. Also used was a filter that isolates hydrogen emission that emanates from bright star-forming regions dotting the spiral arms.

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.

For more information visit http://www.nasa.gov/mission_pages/hubble/science/pinwheel.html

Thursday, October 21, 2010

New Cometary Phenomenon Greets Approaching Spacecraft

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Recent observations of comet Hartley 2 have scientists scratching their heads, while they anticipate a flyby of the small, icy world on Nov. 4.

A phenomenon was recorded by imagers aboard NASA's Deep Impact spacecraft from Sept. 9 to 17 during pre-planned scientific observations of the comet. These observations, when coupled with expected images during the closest encounter with Hartley 2 on Nov. 4, will become the most detailed look yet at a comet's activity during its pass through the inner-solar system.

"On Earth, cyanide is known as a deadly gas. In space it's known as one of the most easily observed ingredients that is always present in a comet," said Mike A'Hearn of the University of Maryland, College Park. A'Hearn is principal of EPOXI, an extended mission that utilizes the already "in flight" Deep Impact spacecraft. "Our observations indicate that cyanide released by the comet increased by a factor of five over an eight-day period in September without any increase in dust emissions," A'Hearn said. "We have never seen this kind of activity in a comet before, and it could affect the quality of observations made by astronomers on the ground."

The new phenomenon is very unlike typical cometary outbursts, which have sudden onsets and are usually accompanied by considerable dust. It also seems unrelated to the cyanide jets that are sometimes seen in comets. The EPOXI science team believes that astronomers and interested observers viewing the comet from Earth should be aware of this type of activity when planning observations and interpreting their data.

"If observers monitoring Hartley 2 do not take into account this new phenomenon, they could easily get the wrong picture of how the comet is changing as it approaches and recedes from the sun," said A'Hearn.

Cyanide is a carbon-based molecule. It is believed that billions of years ago, a bombardment of comets carried cyanide and other building blocks of life to Earth.

The name EPOXI itself is a combination of the names for the two extended mission components: the extrasolar planet observations, called Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI). The spacecraft will continue to be referred to as "Deep Impact."

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the EPOXI mission for NASA's Science Mission Directorate, Washington. The University of Maryland, College Park, is home to the mission's principal investigator, Michael A'Hearn. Drake Deming of NASA's Goddard Space Flight Center, Greenbelt, Md., is the science lead for the mission's extrasolar planet observations. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-346

Wednesday, October 20, 2010

Prototype NASA Earth Camera Goes for Test Flight

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A team of researchers and collaborators from NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the University of Arizona's College of Optical Sciences in Tucson has successfully conducted the first test flight of a prototype science instrument for a next-generation satellite mission to survey the impacts of aerosols and clouds on global climate change.

The Multiangle SpectroPolarimetric Imager, or MSPI, is a multi-directional multi-wavelength, high-accuracy polarization camera that is a follow-on instrument to the JPL-developed Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra spacecraft. It is a candidate instrument for NASA's Aerosol-Cloud-Ecosystem (ACE) mission, an Earth satellite recommended by the National Research Council in its 2007 Earth Sciences Decadal Survey. ACE mission objectives include characterizing the role of aerosols in changing Earth's energy balance (the balance between incoming solar energy and outgoing heat from Earth), especially their impact on precipitation and cloud formation.

An airborne prototype version of the instrument, the AirMSPI, was checked out Oct. 7 on one of NASA's high-altitude ER-2 Earth Resources aircraft during a two-hour flight from NASA's Dryden Aircraft Operations Facility in Palmdale, Calif.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-342

Tuesday, October 19, 2010

Astronomers Find Weird, Warm Spot on an Exoplanet

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Observations from NASA's Spitzer Space Telescope reveal a distant planet with a warm spot in the wrong place.

The gas-giant planet, named upsilon Andromedae b, orbits tightly around its star, with one face perpetually boiling under the star's heat. It belongs to a class of planets termed hot Jupiters, so called for their scorching temperatures and large, gaseous constitutions.

One might think the hottest part of these planets would be directly under the sun-facing side, but previous observations have shown that their hot spots may be shifted slightly away from this point. Astronomers thought that fierce winds might be pushing hot, gaseous material around.

But the new finding may throw this theory into question. Using Spitzer, an infrared observatory, astronomers found that upsilon Andromedae b's hot spot is offset by a whopping 80 degrees. Basically, the hot spot is over to the side of the planet instead of directly under the glare of the sun.

"We really didn't expect to find a hot spot with such a large offset," said Ian Crossfield, lead author of a new paper about the discovery appearing in an upcoming issue of Astrophysical Journal. "It's clear that we understand even less about the atmospheric energetics of hot Jupiters than we thought we did."

The results are part of a growing field of exoplanet atmospheric science, pioneered by Spitzer in 2005, when it became the first telescope to directly detect photons from an exoplanet, or a planet orbiting a star other than our sun. Since then, Spitzer, along with NASA's Hubble Space Telescope, has studied the atmospheres of several hot Jupiters, finding water, methane, carbon dioxide and carbon monoxide.

In the new study, astronomers report observations of upsilon Andromedae b taken across five days in February of 2009. This planet whips around its star every 4.6 days, as measured using the "wobble," or radial velocity technique, with telescopes on the ground. It does not transit, or cross in front of, its star as many other hot Jupiters studied by Spitzer do.

Spitzer measured the total combined light from the star and planet, as the planet orbited around. The telescope can't see the planet directly, but it can detect variations in the total infrared light from the system that arise as the hot side of the planet comes into Earth's field of view. The hottest part of the planet will give off the most infrared light.

One might think the system would appear brightest when the planet was directly behind the star, thus showing its full sun-facing side. Likewise, one might think the system would appear darkest when the planet swings around toward Earth, showing its backside. But the system was the brightest when the planet was to the side of the star, with its side facing Earth. This means that the hottest part of the planet is not under its star. It's sort of like going to the beach at sunset to feel the most heat. The researchers aren't sure how this could be.

They've guessed at some possibilities, including supersonic winds triggering shock waves that heat material up, and star-planet magnetic interactions. But these are just speculation. As more hot Jupiters are examined, astronomers will test new theories.

"This is a very unexpected result," said Michael Werner, the Spitzer project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., who was not a part of the study. "Spitzer is showing us that we are a long way from understanding these alien worlds."

The Spitzer observations were made before it ran out of its liquid coolant in May 2009, officially beginning its warm mission.

Other authors of the study are Brad Hansen of UCLA; Joseph Harrington at the University of Central Florida, Orlando; James Y-K. Cho of Queen Mary, University of London, United Kingdom; Drake Deming of NASA's Goddard Space Flight Center, Greenbelt, Md.; Kristen Menou of Columbia University, New York, N.Y.; and Sara Seager of the Massachusetts Institute of Technology, Boston.

JPL 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, also in Pasadena.

Monday, October 18, 2010

Sun Prominence NASA Celebrates Solar Week with Education Activities and a NASA Chat

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Eight planets and their moons, tens of thousands of asteroids, and trillions of comets revolve around the sun. One of these is our Earth, orbiting the sun at an average distance of about 92,960,000 miles (149,600,000 kilometers). The sun is a huge, glowing ball that provides light, heat, and other energy to our Earth. The world is observing Solar Week from Oct. 18-22, 2010 -- a great time to learn more about our sun and how it affects our solar system.

On Thursday, Oct. 21 from 3:00 - 4:00 p.m. EDT, Dr. David Hathaway, a solar scientist at NASA's Marshall Space Flight Center, will answer your questions about our sun: how it works, why it has cycles and how it produces solar phenomena -- such as sunspots, solar flares and solar storms.

Join the Chat

To participate in the live chat, simply return to this page http://www.nasa.gov/connect/chat/solar_chat2.html a few minutes before the chat time on Oct. 21. The chat module will appear at the bottom of this page. After you log in, wait for the chat module to be activated at 3:00 p.m. EDT, then ask your questions!

More About Chat Expert David Hathaway


Dr. Hathaway received his doctorate in Astrophysics from the University of Colorado in Boulder, CO in 1979. He worked for two years as a Post-Doctoral Fellow in the Advanced Study Program at the National Center for Atmospheric Research before taking a 3-year position as an Assistant Astronomer at the National Solar Observatory site in Sunspot, NM. He came to NASA’s Marshall Space Flight Center in Huntsville, AL in 1984 where he has been a member of the solar physics group and served as its team leader from 1996 to 2010. He has written over 150 articles on the Sun and solar physics and has received three US patents. He has been the recipient of dozens of awards from within NASA and from the broader scientific community. Hathaway has served on numerous advisory committees as well as elected positions within scientific organizations.

Dr. Hathaway’s primary research interests include the nature and origin of the sunspot cycle and the fluid dynamics of the Sun’s interior. His research includes constructing computer models for flows on the surface of the Sun and analysis programs for extracting those flows from satellite observations. He maintains a database on sunspots, including their sizes and positions, that extends back to the year 1874. This database is widely used by the solar physics community. Data plots, images, and animations produced by Dr. Hathaway are also widely used in many publications by both his scientific colleagues and the scientific press.

For more information visit http://www.nasa.gov/connect/chat/solar_chat2.html

Sunday, October 17, 2010

Carbon Dioxide Controls Earth's Temperature

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Water vapor and clouds are the major contributors to Earth's greenhouse effect, but a new atmosphere-ocean climate modeling study shows that the planet's temperature ultimately depends on the atmospheric level of carbon dioxide.

The study, conducted by Andrew Lacis and colleagues at NASA's Goddard Institute for Space Studies (GISS) in New York, examined the nature of Earth's greenhouse effect and clarified the role that greenhouse gases and clouds play in absorbing outgoing infrared radiation. Notably, the team identified non-condensing greenhouse gases -- such as carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbons -- as providing the core support for the terrestrial greenhouse effect.

Without non-condensing greenhouse gases, water vapor and clouds would be unable to provide the feedback mechanisms that amplify the greenhouse effect. The study's results will be published Friday, Oct. 15 in Science.

A companion study led by GISS co-author Gavin Schmidt that has been accepted for publication in the Journal of Geophysical Research shows that carbon dioxide accounts for about 20 percent of the greenhouse effect, water vapor and clouds together account for 75 percent, and minor gases and aerosols make up the remaining five percent. However, it is the 25 percent non-condensing greenhouse gas component, which includes carbon dioxide, that is the key factor in sustaining Earth’s greenhouse effect. By this accounting, carbon dioxide is responsible for 80 percent of the radiative forcing that sustains the Earth’s greenhouse effect.

The climate forcing experiment described in Science was simple in design and concept -- all of the non-condensing greenhouse gases and aerosols were zeroed out, and the global climate model was run forward in time to see what would happen to the greenhouse effect. Without the sustaining support by the non-condensing greenhouse gases, Earth’s greenhouse effect collapsed as water vapor quickly precipitated from the atmosphere, plunging the model Earth into an icebound state -- a clear demonstration that water vapor, although contributing 50 percent of the total greenhouse warming, acts as a feedback process, and as such, cannot by itself uphold the Earth's greenhouse effect.

"Our climate modeling simulation should be viewed as an experiment in atmospheric physics, illustrating a cause and effect problem which allowed us to gain a better understanding of the working mechanics of Earth’s greenhouse effect, and enabled us to demonstrate the direct relationship that exists between rising atmospheric carbon dioxide and rising global temperature," Lacis said.

The study ties in to the geologic record in which carbon dioxide levels have oscillated between approximately 180 parts per million during ice ages, and about 280 parts per million during warmer interglacial periods. To provide perspective to the nearly 1 C (1.8 F) increase in global temperature over the past century, it is estimated that the global mean temperature difference between the extremes of the ice age and interglacial periods is only about 5 C (9 F).

"When carbon dioxide increases, more water vapor returns to the atmosphere. This is what helped to melt the glaciers that once covered New York City," said co-author David Rind, of NASA's Goddard Institute for Space Studies. "Today we are in uncharted territory as carbon dioxide approaches 390 parts per million in what has been referred to as the 'superinterglacial.'"

"The bottom line is that atmospheric carbon dioxide acts as a thermostat in regulating the temperature of Earth," Lacis said. "The Intergovernmental Panel on Climate Change has fully documented the fact that industrial activity is responsible for the rapidly increasing levels of atmospheric carbon dioxide and other greenhouse gases. It is not surprising then that global warming can be linked directly to the observed increase in atmospheric carbon dioxide and to human industrial activity in general."

For more information visit http://www.nasa.gov/topics/earth/features/co2-temperature.html

Thursday, October 14, 2010

NASA Study of Haiti Quake Yields Surprising Results

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The magnitude 7.0 earthquake that caused more than 200,000 casualties and devastated Haiti's economy in January resulted not from the Enriquillo fault, as previously believed, but from slip on multiple faults -- primarily a previously unknown, subsurface fault -- according to a study published online this week in Nature Geoscience.

In addition, because the earthquake did not involve slip near Earth's surface, the study suggests that it did not release all of the strain that has built up on faults in the area over the past two centuries, meaning that future surface-rupturing earthquakes in this region are likely.

Geophysicist Eric Fielding of NASA's Jet Propulsion Laboratory, Pasadena, Calif., along with lead author Gavin Hayes of the U.S. Geological Survey and other colleagues from USGS, the California Institute of Technology in Pasadena, the University of Texas at Austin, and Nagoya University, Japan, used a combination of seismological observations, geologic field data and satellite geodetic measurements to analyze the earthquake source. Initially the Haiti earthquake was thought to be the consequence of movement along a single fault -- the Enriquillo -- that accommodates the motion between the Caribbean and North American tectonic plates. But scientists in the field found no evidence of surface rupture on that fault.

The researchers found the pattern of surface deformation was dominated by movement on a previously unknown, subsurface thrust fault, named the Léogâne fault, which did not rupture the surface.

Fielding, who processed synthetic aperture radar interferometry data from a Japan Aerospace Exploration Agency (JAXA) satellite used in the study, said, "I was surprised when I saw the satellite data showed the Haiti earthquake must have ruptured a different fault than the major Enriquillo fault, which everybody expected was the source. Without the radar images, we might still be wondering what happened."

Fielding said NASA images acquired after the earthquake over the major fault zones of Hispaniola by the JPL-built Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne instrument will give scientists much more detailed information should another large earthquake occur in the region in the future.

For more information visit http://www.nasa.gov/topics/earth/features/haiti20101014.html

Tuesday, October 12, 2010

Explore Energy with NASA during Earth Science Week

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We all know how it feels to be low on energy after a long day. Or how it feels to be full of energy after a good night’s rest or a good meal. Energy is just as important to Earth’s everyday life as it is to ours.

“Exploring Energy” is the theme of this year’s Earth Science Week, Oct. 10-16. The American Geological Institute hosts Earth Science Week annually in cooperation with various sponsors to engage people in Earth science and encourage stewardship of Earth.

NASA develops, deploys and manages an array of satellites that monitor and measure energy as it flows into, through and out of the Earth system. During Earth Science Week, a series of short videos will be posted to NASA’s Earth Science Week website at http://climate.nasa.gov/esw2010. Aimed at educators, the videos will present activities for different grade levels that highlight how NASA explores Earth’s energy, such as the energy that fuels hurricanes.

In addition, NASA has contributed to the following materials included in an educator kit designed to help teachers engage students in Earth science before, during and after this special week:

  • NASA Climate and Energy Education Resources – A two-sided color information sheet lists NASA websites and other resources for Earth science news, data and imagery, and education activities and programs.
  • Web Ranger Bookmark – An oversized color bookmark contains information about WebRangers, a National Park Service program through which kids can explore national parks, monuments and historic sites. The WebRangers website includes a series of activities on climate change and its potential impact on families, neighborhoods and national parks. This series and the bookmark were developed by the National Park Service, NASA and the U.S. Fish and Wildlife Service.
  • Tour of the Electromagnetic Spectrum DVD – A NASA video uses 3-D animations to explain the electromagnetic spectrum and shows examples of how people interact with it on a daily basis. The video is also available online at http://missionscience.nasa.gov/nasascience/ems_full_video.html , and a companion educators guide can be downloaded at [link to be made available in next couple weeks].
  • Earth's Energy Budget Lithograph – A two-sided lithograph features a full-page color diagram illustrating the various kinds and amounts of energy that enter and leave the Earth system.
  • The GLOBE Earth System Science Poster Learning Activities – An activities guide examines connections among environmental phenomena at the local, regional and global scales. The activities help students understand that the environment is a result of the interplay among many processes that take place on varying scales of time and space.
  • Solar Cell Energy Nationwide Learning Activity – A MY NASA DATA lesson for grades 7-12 is featured as the March learning activity in the Earth Science Week 2010-2011 Earth Science Activity Calendar. The activity text provides background information about the sun’s energy, what happens to it upon entering Earth’s atmosphere, and the factors impacting the amount of energy produced by solar panels. Students use NASA data to determine areas of the country that are most likely to produce solar energy.
For more information visit http://www.nasa.gov/topics/earth/features/esw2010.html

Monday, October 11, 2010

New Russian Resupply Vehicle Docks to Station

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The 39th ISS Progress resupply vehicle automatically docked to the aft port of the Zvezda service module of the International Space Station at 7:58 a.m. EDT Sept. 12 using the Kurs automated rendezvous system.

Progress 39 brings to the orbiting complex 1,918 pounds of propellant, 110 pounds of oxygen, 375 pounds of water and 2,645 pounds of spare parts, experiment hardware and other supplies for the station’s six crew members.

After conducting leak checks at the docking interface and opening the hatch to the resupply vehicle, the crew members began the long process of inventorying and unloading the cargo. Once emptied, Progress 39 will be filled with trash and station discards and deorbited to burn in the Earth’s atmosphere like its predecessors.

The ISS Progress 39 launched at 6:22 a.m. EDT Sept. 10 from the Baikonur Cosmodrome in Kazakhstan. Its launch was postponed Sept. 8 for 48 hours due to high winds at the launch pad.

The resupply vehicle that previously occupied Zvezda’s aft port, ISS Progress 38, was deorbited and sent to a fiery demise in the Earth’s atmosphere Sept. 6 after a week of thruster tests conducted by Russian flight controllers.

The newest supply ship joins three other Russian vehicles docked at the station, including the two Soyuz spacecraft, which carried the station’s current residents to the station and will return them to Earth, and the ISS Progress 37 resupply vehicle, which is scheduled to undock Oct. 26.

The Progress is similar in appearance and some design elements to the Soyuz spacecraft. The aft module, the instrumentation and propulsion module, is nearly identical.

But the second of the three Progress sections is a refueling module, and the third, uppermost as the Progress sits on the launch pad, is a cargo module. On the Soyuz, the descent module, where the crew is seated on launch and which returns them to Earth, is the middle module and the third is called the orbital module.

For more information visit http://www.nasa.gov/mission_pages/station/expeditions/expedition24/p39_dock.html

Sunday, October 10, 2010

Hubble Astronomers Uncover an Overheated Early Universe

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If you think global warming is bad, 11 billion years ago there was universal warming. During this period, fierce radiation blasts from active galaxies stunted the growth of some small galaxies for approximately 500 million years.

This is the conclusion of a team of astronomers who used the new capabilities of NASA's Hubble Space Telescope to probe the invisible, remote universe. The team's results will be published in the October 20 issue of The Astrophysical Journal.

Using Hubble's Cosmic Origins Spectrograph (COS), the astronomers identified this era, from 11.7 to 11.3 billion years ago, when the ultraviolet light emitted by quasars stripped electrons off helium atoms. The process, known as ionization, heated the intergalactic helium from 18,000 degrees Fahrenheit to nearly 40,000 degrees. This inhibited the gas from gravitationally collapsing to form new generations of stars in some small galaxies.

Because of its greatly improved sensitivity and lower background "noise" compared to previous spectrographs in space, the COS observations were exquisite. They allowed scientists to produce more detailed measurements of the intergalactic helium than previously possible.

"These COS results yield new insight into an important phase in the history of our universe," said Hubble Program Scientist Eric Smith at NASA Headquarters in Washington.

Michael Shull of the University of Colorado in Boulder and his team studied the spectrum of ultraviolet light that was produced by a quasar and found signs of ionized helium. This beacon, like a headlight shining through fog, shines through interspersed clouds of otherwise invisible gas and allows for a core sample of the gas clouds.

The universe went through an initial heat wave more than 13 billion years ago when energy from early massive stars ionized cold interstellar hydrogen from the big bang. This epoch is actually called reionization, because the hydrogen nuclei were originally in an ionized state shortly after the big bang.

The Hubble team found it would take another two billion years before the universe produced sources of ultraviolet radiation with enough energy to reionize the primordial helium that also was cooked up in the big bang. This radiation didn't come from stars, but rather from super massive black holes. The black holes furiously converted some of the gravitational energy of this mass to powerful ultraviolet radiation that would blaze out of galaxies as quasars. The helium's reionization occurred at a transitory time in the universe's history when galaxies collided to ignite quasars.

After the helium was reionized, intergalactic gas again cooled down and dwarf galaxies could resume normal assembly. "I imagine quite a few more dwarf galaxies may have formed if helium reionization had not taken place," Shull said.

So far Shull and his team only have one sightline to measure the helium transition to its ionized state. However, the COS science team plans to use Hubble to look in other directions to determine if helium reionization uniformly took place across the universe.

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.

For more information visit http://www.nasa.gov/mission_pages/hubble/science/overheated.html

Friday, October 8, 2010

Mobile Mars Lab Almost Ready for Curiosity Rover

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The Sample Analysis at Mars (SAM) instrument suite has completed assembly at NASA's Goddard Space Flight Center in Greenbelt, Md., and is nearly ready for a December delivery to NASA's Jet Propulsion Laboratory, Pasadena, Calif., where it will be installed into the Curiosity rover.

The Mars Science Laboratory mission will use SAM and other instruments on Curiosity to examine whether an intriguing area of Mars has had environmental conditions favorable for microbial life and favorable for preserving evidence of life, if it existed. Launch is scheduled for late 2011, with landing in August 2012.

SAM will explore molecular and elemental chemistry relevant to life. It will analyze samples of Martian rock and soil to assess carbon chemistry through a search for organic compounds, and to look for clues about planetary change.

SAM is in flight configuration, meaning its instruments are in the condition they will be in during launch and are ready to begin operations on Mars. The instrument suite (a mass spectrometer, gas chromatograph and tunable laser spectrometer) started final environmental testing this week, which includes vibration and thermal testing to ensure SAM can survive the launch, deep space flight and conditions on Mars.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-331

Thursday, October 7, 2010

'A-Train' Satellites Search for 770 Million Tons of Dust in the Air

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Using data from several research satellites, scientists will spend the next three years trying to understand the climate impacts of about 770 million tons of dust carried into the atmosphere every year from the Sahara Desert.

Some Saharan dust falls back to Earth before it leaves Africa. Some of it streams out over the Atlantic Ocean or Mediterranean Sea, carried on the wind as far away as South America and the southeastern U.S. All of it has an as-yet unmeasured impact on Earth's energy budget and the climate by reflecting sunlight back into space.

"The people who build climate models make some assumptions about dust and its impact on the climate," said Dr. Sundar Christopher, a professor of atmospheric science at The University of Alabama in Huntsville.

Christopher will use a $500,000 grant from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission, developed and managed by NASA's Langley Research Center in Hampton, Va.

CALIPSO is an Earth observing satellite that provides new insight into the role that clouds and atmospheric aerosols play in air quality, weather and climate. Christopher will use both CALIPSO and Aqua satellite data in his research.

Aqua was the first member launched of a group of satellites termed the Afternoon Constellation, or A-Train, a group of satellites that travel in line, one behind the other, along the same track, as they orbit Earth. Combining the information from several instruments gives a more complete answer to many questions about Earth's atmosphere than would be possible from any single satellite observation taken by itself.

Understanding Dust

"We want to learn more about the characteristics of this dust, its concentrations in the atmosphere and its impact on the global energy budget so we can replace those assumptions with real data," Christopher said.

Dust is one kind of particle, or aerosol, that floats around in the atmosphere. Most of the recent research into aerosols has focused on particles made by humans, such as smoke, soot or other types of pollution.

"There has been a lot of research looking at the climate effects of man-made aerosols," Christopher said. "Particles from smoke and burning fossil fuels are tiny, sub-micron size. Many of these tiny particles cool the atmosphere because they reflect sunlight back into space before it has a chance to heat the air. That means less solar energy is available at the surface to heat the planet."

Dust particles have a significant effect on heat energy in the air. Dust absorbs thermal energy rising from the ground and re-radiates it either toward space (and colder temperatures) or back toward the surface.

"One thing we want to do is calculate how reflective dust is, because not all dust is created equal," said Christopher. "We're trying to calculate reflectivity so we can say with precision how much sunlight is being reflected."

The composition and shape of dust particles is very complex. They are not spherical, which makes calculating their energy budget challenging and time consuming. Also, the composition of dust varies depending on which part of the Sahara the dust comes from. Some of it absorbs more solar energy than others.

"Climate models are not very sophisticated in the way they handle dust," Christopher said. "And the long-wave or infrared part is something that has been ignored for a long time. We want to nail down those values."

"NASA researchers are especially interested in understanding how dust might suppress hurricane formation and provide nutrients for marine life," said Langley's Dr. Chip Trepte, the CALIPSO project scientist.

Why the Sahara?

The Sahara contributes about half of all of the dust carried into Earth's atmosphere every year. Studying the Saharan dust is enough of a challenge, in part because it is made of the same stuff as the desert underneath. That means the dust in the atmosphere looks very much like the surface below it. Only in the past few years have new instruments and new techniques been developed that help scientists "see" which is dust and which is desert.

The CALIPSO satellite's instruments include a lidar, which shoots a laser into the atmosphere, then catches light that bounces off particles in the air to learn more about aerosols. CALIPSO is a collaboration between NASA and France's Centre National d'Etudes Spatiales.

For more information visit http://www.nasa.gov/topics/earth/features/modis-dust.html

Wednesday, October 6, 2010

Rising Expectations: NASA Aeronautics Showcased at Balloon Fiesta

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Visitors at the 2010 International Balloon Fiesta in Albuquerque, N.M., not only get the visual stimulation of hundreds of colorful hot-air balloons soaring skyward, but can learn about NASA efforts toward improving aviation via an exhibit focusing on the agency's aeronautics research efforts.

NASA Aeronautics exhibit this year is focusing on its "green aviation" initiative, which seeks to test and integrate technologies for reducing aircraft noise and emissions, maximizing fuel usage and improving air-traffic management. It also features displays on the history of NASA aeronautics research, including a timeline of aviation achievements, a space shuttle tire flown on the shuttle Discovery, cockpit simulators, wind tunnels and even a "virtual airport" where visitors can zoom in to see how NASA’s technology has found its way to use on military, commercial and general aviation aircraft and helicopters.

A display about the Stratospheric Observatory for Infrared Astronomy, which incorporates the world's largest airborne infrared telescope installed in the rear fuselage of a NASA 747SP aircraft, introduces visitors to the infrared spectrum by allowing them to see themselves on a monitor through the lens of an infrared camera.


For more information visit http://www.nasa.gov/centers/dryden/Features/albuquerque_balloon_fiesta_2010.html


Tuesday, October 5, 2010

WISE Captures Key Images of Comet Mission's Destination

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NASA's Wide-field Infrared Survey Explorer, or WISE, caught a glimpse of the comet that the agency's EPOXI mission will visit in November. The WISE observation will help the EPOXI team put together a large-scale picture of the comet, known as Hartley 2.

"WISE's infrared vision provides data that complement what EPOXI will see with its visible-light and near-infrared instruments," said James Bauer, of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It's as if WISE can see an entire country, and EPOXI will visit its capital."

WISE's infrared vision will allow the telescope to get a new estimate of the size of the comet's nucleus, or core, as well as a more thorough look at the sizes of dust particles that surround it. This information, when combined with what EPOXI finds as it gets closer to Hartley 2, will reveal how the comet has changed over time.

On Nov. 4, the EPOXI mission, which uses the already "in flight" Deep Impact flyby spacecraft, will reach its closet approach to Hartley 2. The spacecraft will examine the dusty, icy body in detail as it flies by, providing the best, extended view of a comet in history. WISE and several other ground- and space-based telescopes are participating in the viewing, working together to tackle mysteries about our solar system's origins that are frozen inside comets.

For stargazers, opportunities to view the comet are possible throughout October. On Wednesday, Oct. 20, Hartley 2 will reach its closest approach to Earth since it was discovered in 1986. The comet will be approximately 17.7 million kilometers away (11 million miles) and should be visible with the naked eye near the constellation Perseus if viewed in dark skies. Observers will need binoculars or telescopes from urban areas in the Northern Hemisphere. Southern Hemisphere stargazers will be able to see the comet later in the month.

WISE captured its view of the comet during an ongoing scan of the sky in infrared light. The mission has been busy cataloging hundreds of millions of objects, from comets to distant, powerful galaxies. In late September, it used up its frozen cryogen coolant as expected and began a new phase of its survey. Called the NEOWISE Post-Cryogenic Mission, it primarily focuses on finding additional asteroids and comets. To date, the WISE mission has observed more than 150,000 asteroids and 110 comets, including Hartley 2.

"Astronomers can reference our catalogue to get detailed infrared data about their favorite asteroid or comet," said Amy Mainzer, the principal investigator of NEOWISE at JPL. "Space missions can also use our observations for more information on their targets, as EPOXI is doing."

WISE's view of Hartley 2 was taken on May 10, 2010. It gives astronomers a unique look at the comet, complementing what other telescopes can see. Because WISE scanned the whole sky, it captured the most extensive view of Hartley 2's trail, the dusty path left by the comet on its repeated journey around the sun.

Bauer said, "We want to know how the comet behaves as it comes toward the sun and out of deep freeze. The WISE image is one critical puzzle piece of many that will give a comprehensive view of the behavior of the comet through the time of the encounter."

The comet started to show signs of activity in the spring, spitting out gas and dust. By July, there were clear jets of gas. "Comparing the dust early on to what we see later with EPOXI helps us understand how the activity started on Hartley 2," said Michael A'Hearn, the principal investigator of EPOXI at the University of Maryland in College Park.

The term EPOXI is a combination of the names for the two extended mission components: the Extrasolar Planet Observations and Characterization (EPOCh), and the Hartley 2 flyby, called the Deep Impact eXtended Investigation (DIXI). The name NEOWISE comes from combining WISE and the acronym for near-Earth object, NEO.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-324

Sunday, October 3, 2010

GOES-13 Sees an Unholy Matrimony: Nicole and Low Pressure Swamp the U.S. East Coast

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In a "marriage" that U.S. east coast residents would object to, the remnants of Tropical Storm Nicole coupled with an upper level low pressure area have dumped record rainfall from the Carolinas to New England on Sept. 30. The GOES-13 Satellite captured that massive "union" of a system as it begins to push off the northeastern U.S. coast today, Oct. 1.

At 1401 UTC (10:01 a.m. EDT) on Oct. 1, the Geostationary Operational Environmental Satellite called GOES-13 captured a visible image of the extensive cloud cover of this coupled system. The GOES image shows the system's cloud cover stretches from New Brunswick and Nova Scotia, Canada, over New England and the Mid-Atlantic states, then southeast over the Atlantic all the way to Puerto Rico.

The GOES series of satellites are managed by the National Oceanic and Atmospheric Administration (NOAA), and GOES-13 keeps an eye on the weather over the eastern half of the U.S. NASA's GOES Project, located at the NASA Goddard Space Flight Center in Greenbelt, Md. uses the data from the GOES satellites and creates images and animations of weather systems.

NOAA's Hydrometeorological Prediction Center noted on Friday, Oct. 1, that "Heavy rains will continue to drench the northeastern (U.S.) coast throughout the day Friday. The east coast deluge will finally draw to a close in the early hours Saturday morning."

The frontal boundary had lingered over the U.S. east coast for over 24 hours and is forecast to push off-shore late Saturday, clearing skies behind it as cold, Canadian high pressure will build in.

Some of the rainfall totals were impressive from Sept. 30. The Baltimore Washington International Airport recorded a record-breaking 6.02 inches of rain. That's about one and a half months of rainfall in 24 hours. Washington D.C.'s Reagan National Airport recorded 4.66 inches of rain, also breaking a record for that day.

To the west, Martinsburg, W.Va. received 3.29 inches of rain yesterday. Further south, Norfolk Va. International Airport recorded 7.85 inches of rainfall while Richmond, Va. broke a record with 3.69 inches of rain. New Bern, N.C. received a record-breaking 8.93 inches while in Jacksonville, N.C., a foot of rain fell in six hours during the morning hours.

As the system moved northward on Sept. 30, its heavy rainfall had not yet been totally experienced, but it still broke records. Its rainfall there today is expected to create more records. On Sept. 30, however, Newark, N.J. received 1.21" of rain in 24 hours and broke a record. The National Weather Service reported that Bridgeport, Conn. received 0.73 inches, which established a new record for rainfall on Sept. 30.

On Oct. 1, GOES-13 satellite imagery showed that the system was still drenching Vermont, New Hampshire, Maine, Connecticut, Rhode Island and Massachusetts today. Although this unholy union of the upper-level low and Nicole's remnants are expected to be off the coast and over the Atlantic Ocean late Saturday, there are other rainmakers in the tropics that NASA is watching.

At NASA Goddard, one of the images created from GOES satellite imagery is called a "full-disk" image. In today's full-disk image there are two other areas of tropical disturbances that have caught the attention of forecasters.

One area of disturbed weather is called "System 97L" and it contains disorganized showers and thunderstorms. That low pressure area is about 900 miles of the Lesser Antilles in the Atlantic Ocean. The system is moving west at between 15 and 20 mph. Forecasters at the National Hurricane Center noted that the upper-level winds are expected to weaken near this system, allowing for more development over the weekend. They've given System 97L a 40 percent chance of becoming a tropical depression over the weekend.

The other area of disturbed weather has a much lesser chance of developing over the weekend. That is a broad trough of low pressure in the Northern Caribbean. A trough is an elongated area of low pressure, just like the one that lingered over the eastern U.S. and brought the deluge. This second low pressure area doesn't appear to be developing. However, it is expected to bring locally heavy rainfall over the weekend to northern Central America, the Cayman Islands, eastern Cuba, Jamaica and Hispaniola and that will keep the GOES-13 satellite busy.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_Nicole.html