NASA GRAIL Returns First Student-Selected Moon Images

PASADENA, Calif. -- One of two NASA spacecraft orbiting the moon has beamed back the first student-requested pictures of the lunar surface from its onboard camera. Fourth grade students from the Emily Dickinson Elementary School in Bozeman, Mont., received the honor of making the first image selections by winning a nationwide competition to rename the two spacecraft.

The image was taken by the MoonKam, or Moon Knowledge Acquired by Middle school students. Previously named Gravity Recovery And Interior Laboratory (GRAIL) A and B, the twin spacecraft are now called Ebb and Flow. Both washing-machine-sized orbiters carry a small MoonKAM camera. Over 60 student–requested images were taken by the Ebb spacecraft from March 15-17 and downlinked to Earth March 20.

"MoonKAM is based on the premise that if your average picture is worth a thousand words, then a picture from lunar orbit may be worth a classroom full of engineering and science degrees," said Maria Zuber, GRAIL mission principal investigator from the Massachusetts Institute of Technology in Cambridge, Mass. "Through MoonKAM, we have an opportunity to reach out to the next generation of scientists and engineers. It is great to see things off to such a positive start."

GRAIL is NASA's first planetary mission to carry instruments fully dedicated to education and public outreach. Students will select target areas on the lunar surface and request images to study from the GRAIL MoonKAM Mission Operations Center in San Diego.

The MoonKAM program is led by Sally Ride, America's first woman in space, and her team at Sally Ride Science in collaboration with undergraduate students at the University of California in San Diego. More than 2,700 schools spanning 52 countries are using the MoonKAM cameras.

"What might seem like just a cool activity for these kids may very well have a profound impact on their futures," Ride said. "The students really are excited about MoonKAM, and that translates into an excitement about science and engineering."

Launched in September 2011, Ebb and Flow will answer longstanding questions about the moon and give scientists a better understanding of how Earth and other rocky planets in the solar system formed.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the GRAIL mission for NASA's Science Mission Directorate in Washington. The Massachusetts Institute of Technology, Cambridge, is home to the mission's principal investigator, Maria Zuber. GRAIL is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.

NASA GRACE Data Hit Big Apple on World Water Day

To highlight declines in the world's groundwater supplies, a new visualization of Earth's groundwater reserves, created in part with space data from the joint NASA/German Aerospace Center (DLR) Gravity Recovery and Climate Experiment (GRACE) mission, debuted on New York's Times Square on March 22, International World Water Day.

The 30-second animation, titled "Visualizing Seasonal and Long-term Changes in Groundwater Levels," will be on display several times each hour through April 22 on Times Square's massive Thomson Reuters and NASDAQ digital signboards. Viewers of the interactive animation are invited to use their mobile devices to submit their city and add a graph to the sign.

Netherlands designer Richard Vijgen developed the animation using GRACE data analyzed by professor Jay Famiglietti, director of the UC Center for Hydrologic Modeling at the University of California, Irvine; and from United States Geological Survey data supplied by Leonard Konikow. Vijgen was the winning entry in an international design visualization competition sponsored by the organization HeadsUP!, in collaboration with Visualizing.org. Founded by digital media artist Peggy Weil, HeadsUp! challenges designers to visualize critical global issues and create a shared sign for the public square.

Groundwater is a critical, but often overlooked, natural resource. According to a U.N. report, more than 1.5 billion people around the world depend on groundwater for their drinking water. It comes from the natural percolation of precipitation and other surface waters down through Earth's soil and rock, accumulating in cavities and layers of porous rock, gravel, sand or clay. Groundwater levels respond slowly to changes in weather and can take months or years to replenish once pumped for irrigation or other uses.

Famiglietti's analyses show that groundwater is being depleted at alarming rates in many of the world's major aquifers. "The GRACE data set is exciting, because it gives us the first global pictures of Earth's changing freshwater," he said.

The twin GRACE satellites, which celebrated their 10th year in orbit this week, measure minute changes in Earth's gravity field by measuring micron-scale variations in the separation between the two spacecraft, flying in formation 137 miles (220 kilometers) apart in low Earth orbit. These variations in gravitational pull are caused by local changes in Earth's mass. Masses of water, ice, air and solid Earth can be moved by weather patterns, seasonal change, climate change and even tectonic events such as large earthquakes. GRACE was developed by NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The depletion of groundwater from large aquifers due to drought and human activities affects gravity enough to provide a signal that GRACE can measure, in concert with other remote sensing data. After accounting for other mass variations, such changes in gravity can be translated into an equivalent change in water. GRACE has been used to detect major depletion of groundwater in northern India, California's Central Valley and elsewhere around the globe.

Groundwater levels are monitored by local sensors as well as from space with GRACE, but the data are formatted for expert hydrologists, rather than concerned citizens. Underground and out of sight, the public lacks a clear indicator of changing groundwater levels. By using the GRACE satellite data, HeadsUP! offered designers the chance to visualize the water under the surface of Earth, as "seen" from space.

What's Next For NASA?

The end of the space shuttle program does not mean the end of NASA, or even of NASA sending humans into space. NASA has a robust program of exploration, technology development and scientific research that will last for years to come. Here is what's next for NASA:

Exploration
NASA is designing and building the capabilities to send humans to explore the solar system, working toward a goal of landing humans on Mars. We will build the Multi-Purpose Crew Vehicle, based on the design for the Orion capsule, with a capacity to take four astronauts on 21-day missions.

NASA is also moving forward with the development of the Space Launch System -- an advanced heavy-lift launch vehicle that will provide an entirely new national capability for human exploration beyond Earth's orbit. The SLS rocket will use a liquid hydrogen and liquid oxygen propulsion system, which will include shuttle engines for the core stage and the J-2X engine for the upper stage.

We are developing the technologies we will need for human exploration of the solar system, including solar electric propulsion, refueling depots in orbit, radiation protection and high-reliability life support systems.

International Space Station
The International Space Station is the centerpiece of our human spaceflight activities in low Earth orbit. The ISS is fully staffed with a crew of six, and American astronauts will continue to live and work there in space 24 hours a day, 365 days a year. Part of the U.S. portion of the station has been designated as a national laboratory, and NASA is committed to using this unique resource for scientific research.

The ISS is a test bed for exploration technologies such as autonomous refueling of spacecraft, advanced life support systems and human/robotic interfaces. Commercial companies are well on their way to providing cargo and crew flights to the ISS, allowing NASA to focus its attention on the next steps into our solar system.

Aeronautics
NASA is researching ways to design and build aircraft that are safer, more fuel-efficient, quieter, and environmentally responsible. We are also working to create traffic management systems that are safer, more efficient and more flexible. We are developing technologies that improve routing during flights and enable aircraft to climb to and descend from their cruising altitude without interruption.

We believe it is possible to build an aircraft that uses less fuel, gives off fewer emissions, and is quieter, and we are working on the technologies to create that aircraft. NASA is also part of the government team that is working to develop the Next Generation Air Transportation System, or NextGen, to be in place by the year 2025. We will continue to validate new, complex aircraft and air traffic control systems to ensure that they meet extremely high safety levels.

Science
NASA is conducting an unprecedented array of missions that will seek new knowledge and understanding of Earth, the solar system and the universe. NASA has observatories in Earth orbit and deep space, spacecraft visiting the moon and other planetary bodies, and robotic landers, rovers, and sample return missions. NASA's science vision encompasses questions as practical as hurricane formation, as enticing as the prospect of lunar resources, and as profound as the origin of the Universe.

THE NEXT BIG SOLAR SYSTEM

June 21, 2011: In Sept. 1859, on the eve of a below-average solar cycle, the sun unleashed one of the most powerful storms in centuries. The underlying flare was so unusual, researchers still aren't sure how to categorize it. The blast peppered Earth with the most energetic protons in half-a-millennium, induced electrical currents that set telegraph offices on fire, and sparked Northern Lights over Cuba and Hawaii.

This week, officials have gathered at the National Press Club in Washington DC to ask themselves a simple question: What if it happens again?

"A similar storm today might knock us for a loop," says Lika Guhathakurta, a solar physicist at NASA headquarters. "Modern society depends on high-tech systems such as smart power grids, GPS, and satellite communications--all of which are vulnerable to solar storms."

She and more than a hundred others are attending the fifth annual Space Weather Enterprise Forum—"SWEF" for short. The purpose of SWEF is to raise awareness of space weather and its effects on society especially among policy makers and emergency responders. Attendees come from the US Congress, FEMA, power companies, the United Nations, NASA, NOAA and more.

As 2011 unfolds, the sun is once again on the eve of a below-average solar cycle—at least that’s what forecasters are saying. The "Carrington event" of 1859 (named after astronomer Richard Carrington, who witnessed the instigating flare) reminds us that strong storms can occur even when the underlying cycle is nominally weak.

In 1859 the worst-case scenario was a day or two without telegraph messages and a lot of puzzled sky watchers on tropical islands.

In 2011 the situation would be more serious. An avalanche of blackouts carried across continents by long-distance power lines could last for weeks to months as engineers struggle to repair damaged transformers. Planes and ships couldn’t trust GPS units for navigation. Banking and financial networks might go offline, disrupting commerce in a way unique to the Information Age. According to a 2008 report from the National Academy of Sciences, a century-class solar storm could have the economic impact of 20 hurricane Katrinas.

As policy makers meet to learn about this menace, NASA researchers a few miles away are actually doing something about it:

"We can now track the progress of solar storms in 3 dimensions as the storms bear down on Earth," says Michael Hesse, chief of the GSFC Space Weather Lab and a speaker at the forum. "This sets the stage for actionable space weather alerts that could preserve power grids and other high-tech assets during extreme periods of solar activity."

Cassini Sends Back Postcards of Saturn Moons

On Jan. 31, 2011, NASA's Cassini spacecraft passed by several of Saturn's intriguing moons, snapping images along the way. Cassini passed within about 60,000 kilometers (37,282 miles) of Enceladus and 28,000 kilometers (17,398 miles) of Helene. It also caught a glimpse of Mimas in front of Saturn's rings. In one of the images, Cassini is looking at the famous jets erupting from the south polar terrain of Enceladus.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo.

Tracking the Origins of Speedy Space Particles

NASA's Time History of Events and Macroscale Interaction during Substorms (THEMIS) spacecraft combined with computer models have helped track the origin of the energetic particles in Earth's magnetic atmosphere that appear during a kind of space weather called a substorm. Understanding the source of such particles and how they are shuttled through Earth's atmosphere is crucial to better understanding the Sun's complex space weather system and thus protect satellites or even humans in space.

The results show that these speedy electrons gain extra energy from changing magnetic fields far from the origin of the substorm that causes them. THEMIS, which consists of five orbiting satellites, helped provide these insights when three of the spacecraft traveled through a large substorm on February 15, 2008. This allowed scientists to track changes in particle energy over a large distance. The observations were consistent with numerical models showing an increase in energy due to changing magnetic fields, a process known as betatron acceleration.

"The origin of fast electrons in substorms has been a puzzle," says Maha Ashour-Abdalla, the lead author of a Nature Physics paper that appeared online on January 30, 2011 on the subject and a physicist at the University of California, Los Angeles. "It hasn't been clear until now if they got their burst of speed in the middle of the storm, or from some place further away."

Runaway Star Plows Through Space

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

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

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

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

Voyager Celebrates 25 Years Since Uranus Visit

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

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

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

NASA’s Glory Mission Will Study Key Pieces of the Climate Puzzle

Earth’s climate continues to change at a rapid pace.

Last week, NASA announced that 2010 was tied as the warmest year on record. Likewise, the last decade was the warmest in the 130-year global temperature record maintained by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York City.

Meanwhile, at Vandenberg Air Force Base in California, engineers are preparing NASA’s next Earth-observing mission -- a satellite called Glory -- for launch in late February. The satellite, which contains two instruments that will monitor key parts of the climate system, aims to offer a new stream of data that climatologists will use as part of an ongoing effort to improve the accuracy of climate models.

NASA Spacecraft Prepares for Valentine's Day Comet Rendezvous

NASA's Stardust-NExT spacecraft is nearing a celestial date with comet Tempel 1 at approximately 8:37 p.m. PST (11:37 p.m. EST), on Feb. 14. The mission will allow scientists for the first time to look for changes on a comet's surface that occurred following an orbit around the sun.

The Stardust-NExT, or New Exploration of Tempel, spacecraft will take high-resolution images during the encounter, and attempt to measure the composition, distribution, and flux of dust emitted into the coma, or material surrounding the comet's nucleus. Data from the mission will provide important new information on how Jupiter-family comets evolved and formed.

The mission will expand the investigation of the comet initiated by NASA's Deep Impact mission. In July 2005, the Deep Impact spacecraft delivered an impactor to the surface of Tempel 1 to study its composition. The Stardust spacecraft may capture an image of the crater created by the impactor. This would be an added bonus to the huge amount of data that mission scientists expect to obtain.

Cosmonauts to Perform 27th Russian Space Station Spacewalk

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

Expedition 26 Flight Engineers Dmitry Kondratyev and Oleg Skripochka are scheduled to float outside the Pirs airlock at 9:20 a.m. EST to beg

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in the six-hour excursion. Both spacewalkers will wear Russian Orlan-MK spacesuits.

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

Planck Mission Peels Back Layers of the Universe

The Planck mission released a new data catalogue Tuesday from initial maps of the entire sky. The catalogue includes thousands of never-before-seen dusty cocoons where stars are forming, and some of the most massive clusters of galaxies ever observed. Planck is a European Space Agency mission with significant contributions from NASA.

"NASA is pleased to support this important mission, and we have eagerly awaited Planck's first discoveries," said Jon Morse, NASA's Astrophysics Division director at the agency's headquarters in Washington. "We look forward to continued collaboration with ESA and more outstanding science to come."

Planck launched in May 2009 on a mission to detect light from just a few hundred thousand years after the Big Bang, an explosive event at the dawn of the universe approximately 13.7 billion years ago. The spacecraft's state-of-the-art detectors ultimately will survey the whole sky at least four times, measuring the cosmic microwave background, or radiation left over from the Big Bang. The data will help scientists decipher clues about the evolution, fate and fabric of our universe. While these cosmology results won't be ready for another two years or so, early observations of specific objects in our Milky Way galaxy, as well as more distant galaxies, are being released.

NASA'S Kepler Mission Discovers Its First Rocky Planet

NASA's Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system.

The discovery of this so-called exoplanet is based on more than eight months of data collected by the spacecraft from May 2009 to early January 2010.

"All of Kepler's best capabilities have converged to yield the first solid evidence of a rocky planet orbiting a star other than our sun," said Natalie Batalha, Kepler's deputy science team lead at NASA's Ames Research Center in Moffett Field, Calif., and primary author of a paper on the discovery accepted by the Astrophysical Journal. "The Kepler team made a commitment in 2010 about finding the telltale signatures of small planets in the data, and it's beginning to pay off."

Kepler's ultra-precise photometer measures the tiny decrease in a star's brightness that occurs when a planet crosses in front of it. The size of the planet can be derived from these periodic dips in brightness. The distance between the planet and the star is calculated by measuring the time between successive dips as the planet orbits the star.

NASA Chat: The Quest for Planets

A new planet discovery will be announced Monday Jan. 10 during the 'Exoplanets & Their Host Stars' presentation at the American Astronomical Society (AAS) conference in Seattle, Washington.

Kepler is NASA's first mission to look specifically for Earth-size planets in the habitable zones (areas where liquid water could exist) around stars like our sun. Kepler will spend 3-1/2 years surveying more than 100,000 stars in the Cygnus-Lyra region of our Milky Way galaxy. More than 300 exoplanets have been discovered previously, most of which are low-density gas giants such as Jupiter or Saturn in our own solar system.

Natalie Batalha of the NASA Kepler Mission Team will be online answering your questions about this new planet finding on Monday, Jan. 10 from 3:30 p.m. to 4:30 p.m. EST / 12:30 p.m. to 1:30 p.m. PST. Natalie will be chatting with you live from the conference in Seattle.

Rover Will Spend 7th Birthday at Stadium-Size Crater

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter captured a Dec. 31, 2010, view of the Mars Exploration Rover Opportunity on the southwestern rim of a football-field-size crater called "Santa Maria."

Opportunity arrived at the western edge of Santa Maria crater in mid-December and will spend about two months investigating rocks there. That investigation will take Opportunity into the beginning of its eighth year on Mars. Opportunity landed in the Meridiani Planum region of Mars on Jan. 25, 2004, Universal Time (Jan. 24, Pacific Time) for a mission originally planned to last for three months.

Cassini Sees Saturn on a Cosmic Dimmer Switch

Like a cosmic lightbulb on a dimmer switch, Saturn emitted gradually less energy each year from 2005 to 2009, according to observations by NASA's Cassini spacecraft. But unlike an ordinary bulb, Saturn's southern hemisphere consistently emitted more energy than its northern one. On top of that, energy levels changed with the seasons and differed from the last time a spacecraft visited Saturn in the early 1980s. These never-before-seen trends came from a detailed analysis of long-term data from the composite infrared spectrometer (CIRS), an instrument built by NASA's Goddard Space Flight Center in Greenbelt, Md., as well as a comparison with earlier data from NASA's Voyager spacecraft. When combined with information about the energy coming to Saturn from the sun, the results could help scientists understand the nature of Saturn's internal heat source.

"The fact that Saturn actually emits more than twice the energy it absorbs from the sun has been a puzzle for many decades now," said Kevin Baines, a Cassini team scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and a co-author on a new paper about Saturn's energy output. "What generates that extra energy? This paper represents the first step in that analysis."

The research, reported this week in the Journal of Geophysical Research-Planets, was led by Liming Li of Cornell University in Ithaca, N.Y. (now at the University of Houston).

"The Cassini CIRS data are very valuable because they give us a nearly complete picture of Saturn," Li said. "This is the only single data set that provides so much information about this planet, and it's the first time that anybody has been able to study the power emitted by one of the giant planets in such detail."

The planets in our solar system lose energy in the form of heat radiation in wavelengths that are invisible to the human eye. The CIRS instrument picks up wavelengths in the thermal infrared region, far enough beyond red light where the wavelengths correspond to heat emission.

"In planetary science, we tend to think of planets as losing power evenly in all directions and at a steady rate," Li said. "Now we know Saturn is not doing that." (Power is the amount of energy emitted per unit of time.)

Instead, Saturn's flow of outgoing energy was lopsided, with its southern hemisphere giving off about one-sixth more energy than the northern one, Li explains. This effect matched Saturn's seasons: during those five Earth-years, it was summer in the southern hemisphere and winter in the northern one. (A season on Saturn lasts about seven Earth-years.) Like Earth, Saturn has these seasons because the planet is tilted on its axis, so one hemisphere receives more energy from the sun and experiences summer, while the other receives less energy and is shrouded in winter. Saturn's equinox, when the sun was directly over the equator, occurred in August 2009.

In the study, Saturn's seasons looked Earth-like in another way: in each hemisphere, its effective temperature, which characterizes its thermal emission to space, started to warm up or cool down as a change of season approached. The effective temperature provides a simple way to track the response of Saturn's atmosphere to the seasonal changes, which is complicated because Saturn's weather is variable and the atmosphere tends to retain heat. Cassini's observations revealed that the effective temperature in the northern hemisphere gradually dropped from 2005 to 2008 and started to warm up again by 2009. In the southern hemisphere, the effective temperature cooled from 2005 to 2009.

The emitted energy for each hemisphere rose and fell along with the effective temperature. Even so, during this five-year period, the planet as a whole seemed to be slowly cooling down and emitting less energy.

To find out if similar changes were happening one Saturn-year ago, the researchers looked at data collected by the Voyager spacecraft in 1980 and 1981 and did not see the imbalance between the southern and northern hemispheres. Instead, the two regions were much more consistent with each other.

Why wouldn't Voyager have seen the same summer-versus-winter difference between the two hemispheres? One explanation is that cloud patterns at depth could have fluctuated, blocking and scattering infrared light differently.

"It's reasonable to think that the changes in Saturn's emitted power are related to cloud cover," says Amy Simon-Miller, who heads the Planetary Systems Laboratory at Goddard and is a co-author on the paper. "As the amount of cloud cover changes, the amount of radiation escaping into space also changes. This might vary during a single season and from one Saturn-year to another. But to fully understand what is happening on Saturn, we will need the other half of the picture: the amount of power being absorbed by the planet."

Scientists will be doing that as a next step by comparing the instrument's findings to data obtained by Cassini's imaging cameras and infrared mapping spectrometer instrument. The spectrometer, in particular, measures the amount of sunlight reflected by Saturn. Because scientists know the total amount of solar energy delivered to Saturn, they can derive the amount of sunlight absorbed by the planet and discern how much heat the planet itself is emitting. These calculations help scientists tackle what the actual source of that warming might be and whether it changes.

Better understanding Saturn's internal heat flow "will significantly deepen our understanding of the weather, internal structure and evolution of Saturn and the other giant planets," Li said.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA Goddard, where the instrument was built.

More Cassini information is available at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Dark Reflections in the Southern Cross

NASA's Wide-field Infrared Survey Explorer, or WISE, captured this colorful image of the reflection nebula IRAS 12116-6001. This cloud of interstellar dust cannot be seen directly in visible light, but WISE's detectors observed the nebula at infrared wavelengths.

In images of reflection nebulae taken with visible light, clouds of dust reflect the light of nearby stars. The dust is warmed to relatively cool temperatures by the starlight and glows with infrared light, which WISE can detect. Reflection nebulae are of interest to astronomers because they are often the sites of new star formation.

The bright blue star on the right side of the image is the variable star Epsilon Crucis. In the Bayer system of stellar nomenclature, stars are given names based on their relative brightness within a constellation. The Greek alphabet is used to designate the star's apparent brightness compared to other stars in the same constellation. "Alpha" is the brightest star in the constellation, "beta" the second brightest, and so on. In this case, "epsilon" is the fifth letter of the Greek alphabet, so Epsilon Crucis is the fifth brightest star in the constellation Crux.

Crux is a well-known constellation that can be easily seen by observers in the Southern Hemisphere and from low northern latitudes. Also known as the Southern Cross, Crux is featured in many country's flags, including Australia, Brazil and New Zealand (although New Zealand's flag does not include Epsilon Crucis).

The colors used in this image represent specific wavelengths of infrared light. The blue color of Epsilon Crucis represents light emitted at 3.4 and 4.6 microns. The green-colored star seen beside Epsilon Crucis is emitting light at 12 microns. This star is IRAS 12194-6007, a carbon star that is near the end of its lifecycle. Since the infrared wavelengths emitted by this star are longer than those from Epsilon Crucis, it is cooler. The green and red colors seen in the reflection nebula represent 12- and 22-micron light coming from the nebula's dust grains warmed by nearby stars.

Cassini Catches Saturn Moons in Paintball Fight

PASADENA, Calif. – Scientists using data from NASA's Cassini spacecraft have learned that distinctive, colorful bands and splotches embellish the surfaces of Saturn's inner, mid-size moons. The reddish and bluish hues on the icy surfaces of Mimas, Enceladus, Tethys, Dione and Rhea appear to be the aftermath of bombardments large and small.

A paper based on the findings was recently published online in the journal Icarus. In it, scientists describe prominent global patterns that trace the trade routes for material exchange between the moons themselves, an outer ring of Saturn known as the E ring and the planet's magnetic environment. The finding may explain the mysterious Pac-Man thermal pattern on Mimas, found earlier this year by Cassini scientists, said lead author Paul Schenk, who was funded by a Cassini data analysis program grant and is based at the Lunar and Planetary Institute in Houston.

"The beauty of it all is how the satellites behave as a family, recording similar processes and events on their surfaces, each in its own unique way," Schenk said. "I don't think anyone expected that electrons would leave such obvious fingerprints on planetary surfaces, but we see it on several moons, including Mimas, which was once thought to be rather bland."

Schenk and colleagues processed raw images obtained by Cassini's imaging cameras from 2004 to 2009 to produce new, high-resolution global color maps of these five moons. The new maps used camera frames shot through visible-light, ultraviolet and infrared filters which were processed to enhance our views of these moons beyond what could be seen by the human eye.

The new images are available at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

"The richness of the Cassini data set – visible images, infrared images, ultraviolet images, measurements of the radiation belts – is such that we can finally 'paint a picture' as to how the satellites themselves are 'painted,'" said William B. McKinnon, one of six co-authors on the paper. McKinnon is based at Washington University in St. Louis and was also funded by the Cassini data analysis program.

Icy material sprayed by Enceladus, which makes up the misty E ring, appears to leave a brighter, blue signature. The pattern of bluish material on Enceladus, for example, indicates that the moon is covered by the fallback of its own "breath."

Enceladean spray also appears to splatter the parts of Tethys, Dione and Rhea that run into the spray head-on in their orbits around Saturn. But scientists are still puzzling over why the Enceladean frost on the leading hemisphere of these moons bears a coral-colored, rather than bluish, tint.

On Tethys, Dione and Rhea, darker, rust-colored, reddish hues paint the entire trailing hemisphere, or the side that faces backward in the orbit around Saturn. The reddish hues are thought to be caused by tiny particle strikes from circulating plasma, a gas-like state of matter so hot that atoms split into an ion and an electron, in Saturn's magnetic environment. Tiny, iron-rich "nanoparticles" may also be involved, based on earlier analyses by the Cassini visual and infrared mapping spectrometer team.

Mimas is also touched by the tint of Enceladean spray, but it appears on the trailing side of Mimas. This probably occurs because it orbits inside the path of Enceladus, or closer to Saturn, than Tethys, Dione and Rhea.

In addition, Mimas and Tethys sport a dark, bluish band. The bands match patterns one might expect if the surface were being irradiated by high-energy electrons that drift in a direction opposite to the flow of plasma in the magnetic bubble around Saturn. Scientists are still figuring out exactly what is happening, but the electrons appear to be zapping the Mimas surface in a way that matches the Pac-Man thermal pattern detected by Cassini's composite infrared spectrometer, Schenk said.

Schenk and colleagues also found a unique chain of bluish splotches along the equator of Rhea that re-open the question of whether Rhea ever had a ring around it. The splotches do not seem related to Enceladus, but rather appear where fresh, bluish ice has been exposed on older crater rims. Though Cassini imaging scientists recently reported that they did not see evidence in Cassini images of a ring around Rhea, the authors of this paper suggest the crash of orbiting material, perhaps a ring, to the surface of Rhea in the not-too-distant past could explain the bluish splotches.

"Analyzing the image color ratios is a great way to really enhance the otherwise subtle color variations and make apparent some of the processes at play in the Saturn system," said Amanda Hendrix, Cassini deputy project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The Cassini images highlight the importance and potential effects of so-called 'space weathering' that occurs throughout the solar system – on any surface that isn't protected by a thick atmosphere or magnetic field."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

Cassini Gazes at Veiled Titan

NASA's Cassini spacecraft will swing high over Saturn's moon Titan on Friday, Sept. 24, taking a long, sustained look at the hazy moon. At closest approach, Cassini will fly within 8,175 kilometers (5,080 miles) above the hazy moon's surface. This flyby is the first in a series of high-altitude Titan flybys for Cassini over the next year and a half.

Cassini's composite infrared spectrometer instrument will be probing Titan's stratosphere to learn more about its vertical structure as the seasons change. Equinox, when the sun shone directly over the equator, occurred in August 2009, and the northern hemisphere is now in spring.

Another instrument, the visual and infrared mapping spectrometer, will be mapping an equatorial region known as Belet at a resolution of 5 kilometers (3 miles) per pixel. This mosaic will complement the mosaics that were obtained in earlier Titan flybys in January and April. This spectrometer will also look for clouds at northern mid-latitudes and near the poles.

Cassin's visible-light imaging cameras will also be taking images of Titan's trailing hemisphere, or the side that faces backward as Titan orbits around Saturn. If Titan cooperates and has a cloudy day, scientists plan to analyze the images for cloud patterns.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C.

See Beautiful Ontario Lacus: Cassini's Guided Tour

Ontario Lacus, the largest lake in the southern hemisphere of Saturn's moon Titan, turns out to be a perfect exotic vacation spot, provided you can handle the frosty, subzero temperatures and enjoy soaking in liquid hydrocarbon.

Several recent papers by scientists working with NASA's Cassini spacecraft describe evidence of beaches for sunbathing in Titan's low light, sheltered bays for mooring boats, and pretty deltas for wading out in the shallows. They also describe seasonal changes in the lake's size and depth, giving vacationers an opportunity to visit over and over without seeing the same lake twice.

With such frigid temperatures and meager sunlight, you wouldn't think Titan has a lot in common with our own Earth," said Steve Wall, deputy team lead for the Cassini radar team, based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "But Titan continues to surprise us with activity and seasonal processes that look marvelously, eerily familiar."

Cassini arrived at Saturn in 2004 when the southern hemisphere of the planet and its moons were experiencing summer. The seasons have started to change toward autumn, with winter solstice darkening the southern hemisphere of Titan in 2017. A year on Titan is the equivalent of about 29 Earth years.

Cassini first obtained an image of Ontario Lacus with its imaging camera in 2004. A paper submitted to the journal Icarus by Alex Hayes, a Cassini radar team associate at the California Institute of Technology in Pasadena, and colleagues finds that the lake's shoreline has receded by about 10 kilometers . This has resulted in a liquid level reduction of about 1 meter per year over a four year period.