Blowing in the Wind: Cassini Helps with Dune Whodunit

The answer to the mystery of dune patterns on Saturn's moon Titan did turn out to be blowing in the wind. It just wasn't from the direction many scientists expected.

Basic principles describing the rotation of planetary atmospheres and data from the European Space Agency's Huygens probe led to circulation models that showed surface winds streaming generally east-to-west around Titan's equatorial belt. But when NASA's Cassini spacecraft obtained the first images of dunes on Titan in 2005, the dunes' orientation suggested the sands and therefore the winds were moving from the opposite direction, or west to east.

Scientists predicted winds in the low latitudes around Titan's equator would blow east-to-west because at higher latitudes the average wind blows west-to-east. The wind forces should balance out, based on basic principles of rotating atmospheres.

Equinoxes occur twice a Titan year, which is about 29 Earth years. During equinox, the sun shines directly over the equator, and heat from the sun creates upwelling in the atmosphere. The turbulent mixing causes the winds to reverse and accelerate. On Earth, this rare kind of wind reversal happens over the Indian Ocean in transitional seasons between monsoons.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the Cassini-Huygens mission for NASA's Science Mission Directorate. The Cassini orbiter was designed, developed and assembled at JPL.

The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. JPL is a division of the California Institute of Technology in Pasadena.

New Spaceship Could Fly People to Private Space Stations

Aerospace heavyweight Boeing is advancing plans for its new capsule-based spaceship, designed to ferry people to and from the International Space Station and future private space stations. The capsule design is part of an effort to fill the void that will be left by the 2011 retirement of NASA's space shuttle fleet.

The new Crew Space Transportation-100 spacecraft is part of the company's $18 million award from NASA under the Commercial Crew Development Space Act Agreement. The award aims to advance the concepts and technology required to build a commercial crew space transportation system.

Boeing's capsule design is one of several efforts by different U.S. companies to develop the first private spaceship capable of flying humans to space. The push fits in with President Barack Obama's new plan for NASA, which calls for commercial spacecraft to take over the role vacated by the space shuttles of transporting astronauts to the space station.Boeing's new spaceship design will look similar to NASA's cone-shaped Apollo and Orion spacecraft.

The Apollo capsules were built to fly astronauts from Earth to the moon in the late 1960s and 1970s. The larger Orion vehicles were part of NASA's Constellation program to return astronauts to the moon, which was cancelled by President Obama as part of his new proposal. The Obama administration did resurrect Orion, though, to serve as a space station lifeboat.

Gigantic Satellite Poses 150-Year menace of Space trash

The European Space Agency will develop into the proprietor of what is perhaps the majority hazardous quantity of space wreckage rotating the Earth for the subsequently 150 years: the 17,636-pound Envisat Earth surveillance satellite.

The space agency will obtain be in charge of the Envisat satellite, which has been extensive to 2013 and come into view to set documentation wherever it goes.

Launched in 2002, Envisat was the largest non-military Earth surveillance satellite ever built. At $2.9 billion in today's dollars, it is one of the mainly luxurious. Its assignment is viewed as a achievement by its users, all the more so insofar as the innovative five year mission has been stretched to 11 years.

Envisat will turn into what space debris experts say is a gigantic problem that will not go away for about 150 years. That is how long it will take for Envisat, given its orbit and its area-to-mass ratio, to be slowly but surely pulled into the Earth's atmosphere With Envisat still prepared ESA's European Space Operations Centre control facility in Darmstadt, Germany, fired Envisat's on-board thrusters to perform a collision avoidance maneuver.

Envisat's 17,636-pound mass unaccompanied would be adequate to put it onto the top tier of space debris threats, even though there are nearly a dozen spent Russian rocket upper stages that weigh as much as or more than Envisat.

Envisat's configuration in orbit makes it a sole concern, even beyond its weight. The satellite in orbit size is 26 meters by 10 meters by five meters. Its group of observing instruments uses a small farm of antennas that likely have become more brittle after a decade in orbit.

With such a little fuel tank, any effort to bring the satellite's orbit down to where it could re-enter the atmosphere would have meant reserved Envisat just a few months after its launch. ESA officials insist that the international guidelines on discarding of debris were not in force when Envisat.

Mars Curiosity Takes First Baby Steps

Like proud parents savoring their baby's very first steps, mission team members gathered in a gallery above a clean room at NASA's Jet Propulsion Laboratory to watch the Mars Curiosity rover roll for the first time.

Engineers and technicians wore "bunny suits" while guiding Curiosity through its first steps, or more precisely, its first roll on the clean room floor. The rover moved forward and backward about 1 meter .

Mars Science Laboratory is scheduled to launch in fall 2011 and land on the Red Planet in August 2012. Curiosity is the largest rover ever sent to Mars. It will carry 10 instruments that will help search an intriguing region of the Red Planet for two things:1. Environments where life might have existed
2. The capacity of those environments to preserve evidence of past life

Arctic Voyage Illuminating Ocean Optics

During NASA's ICESCAPE voyage to the Arctic, scientists have been looking at the phytoplankton in the Arctic's Chukchi Sea -- how many, how big and at what depths they are found. But there are other ways of looking at these small life forms.

"We measure phytoplankton in terms of their pigments and light absorption properties," said Stan Hooker of NASA's Ocean Biology and Biogeo chemistry Calibration and Validation Office at Goddard Space Flight Center, Greenbelt, Md. Hooker, Joaquin Chaves and Aimee Neeley, also of NASA, measure the color of the water. Anything in the water, plankton or not, can influence that color.

On July 2, a crane maneuvered a small boat halfway down the side of the U.S. Coast Guard Cutter Healy the platform for the five-week ICESCAPE mission, NASA's first dedicated oceanographic field campaign, which is studying the physics, chemistry and biology of the ocean and sea ice within a changing Arctic.

Hooker, Chaves and Coast Guard crew boarded the small boat and readied for an expedition away from the stirred water and shadow of the 420-foot Healy. Lowered to the ocean surface, Hooker's team powered away, entering uncharted waters.

Maneuvering over smooth water and around chunks of sea ice, the small boat slowed to a stop near the edge of an ice floe.

Hubble Space Telescope

The hot, blue star HE 0437-5439 has been tossed out of the center of our Milky Way galaxy with enough speed to escape the galaxy's gravitational clutches. The stellar outcast is rocketing through the Milky Way's distant outskirts at 1.6 million miles an hour, high above the galaxy's disk, about 200,000 light-years from the center. The star is destined to roam intergalactic space.

A hundred million years ago, a triple-star system was traveling through the bustling center of our Milky Way galaxy when it made a life-changing misstep. The trio wandered too close to the galaxy's giant black hole, which captured one of the stars and hurled the other two out of the Milky Way. Adding to the stellar game of musical chairs, the two outbound stars merged to form a super- hot, blue star.

This story may seem like science fiction, but astronomers using NASA's Hubble Space Telescope say it is the most likely scenario for a so-called hypervelocity star, known as HE 0437-5439, one of the fastest ever detected. It is blazing across space at a speed of 1.6 million miles hour, three times faster than our Sun's orbital velocity in the Milky Way. Hubble observations confirm that the stellar speedster hails from the Milky Way's core, settling some confusion over where it originally called home.

First Kind Map Depicts Global Forest Heights

Using NASA satellite data, scientists have produced a first of its kind map that details the height of the world’s forests. Although there are other local and regional scale forest canopy maps, the new map is the first that spans the entire globe based on one uniform method.

The work based on data collected by NASA's ICESat, Terra, and Aqua satellites should help scientists build an inventory of how much carbon the world’s forests store and how fast that carbon cycles through ecosystems and back into the atmosphere. Michael Lefsky of the Colorado State University described his results in the journal Geophysical Research Letters.

The new map shows the world’s tallest forests clustered in the Pacific Northwest of North America and portions of Southeast Asia, while shorter forests are found in broad swaths across northern Canada and Eurasia. The map depicts average height over 5 square kilometers , not the maximum heights that any one tree or small patch of trees might attain.

Temperate conifer forests which are extremely moist and contain massive trees such as Douglas fir, western hemlock, redwoods, and sequoias have the tallest canopies, soaring easily above 40 meters . In contrast, boreal forests dominated by spruce, fir, pine, and larch had canopies typically less than 20 meters . Relatively undisturbed areas in tropical rain forests were about 25 meters , roughly the same height as the oak, beeches, and birches of temperate broad leaf forests common in Europe and much of the United States.

The next generation LIDAR measurements of forests and biomass, which will improve the resolution of the map considerably, could come from NASA's Deformation, Ecosystem Structure and Dynamics of Ice satellite, proposed for the latter part of this decade.

NASA's WISE Mission to Complete Extensive Sky Survey

NASA's Wide-field Infrared Survey Explorer will complete its first survey of the entire sky on July 17, 2010. The mission has generated more than one million images so far, of everything from asteroids to distant galaxies.

"Like a globe-trotting shutterbug, WISE has completed a world tour with 1.3 million slides covering the whole sky," said Edward Wright, the principal investigator of the mission at the University of California, Los Angeles.

Some of these images have been processed and stitched together into a new picture being released today. It shows the Pleiades cluster of stars, also known as the Seven Sisters, resting in a tangled bed of wispy dust. The pictured region covers seven square degrees, or an area equivalent to 35 full moons, highlighting the telescope's ability to take wide shots of vast regions of space.

The new picture was taken in February. It shows infrared light from WISE's four detectors in a range of wavelengths. This infrared view highlights the region's expansive dust cloud, through which the Seven Sisters and other stars in the cluster are passing. Infrared light also reveals the smaller and cooler stars of the family.

"The WISE all-sky survey is helping us sift through the immense and diverse population of celestial objects," said Hashima Hasan, WISE Program scientist at NASA Headquarters in Washington. "It's a great example of the high impact science that's possible from NASA's Explorer Program."

The first release of WISE data, covering about 80 percent of the sky, will be delivered to the astronomical community in May of next year. The mission scanned strips of the sky as it orbited around the Earth's poles since its launch last December. WISE always stays over the Earth's day-night line. As the Earth moves around the sun, new slices of sky come into the telescope's field of view. It has taken six months, or the amount of time for Earth to travel halfway around the sun, for the mission to complete one full scan of the entire sky.

For the next three months, the mission will map half of the sky again. This will enhance the telescope's data, revealing more hidden asteroids, stars and galaxies. The mapping will give astronomers a look at what's changed in the sky. The mission will end when the instrument's block of solid hydrogen coolant, needed to chill its infrared detectors, runs out.

"The eyes of WISE have not blinked since launch," said William Irace, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Both our telescope and spacecraft have performed flawlessly and have imaged every corner of our universe, just as we planned."

Meet the Titans: Dust Disk Found Around Massive Star

A new discovery has the potential to answer the long standing question of how massive stars are born and hints at the possibility that planets could form around the galaxy's biggest bodies.

"Astronomers have long been unclear about how the most massive stars form," said Stefan Kraus, a NASA Sagan Exoplanet Fellow and astronomer at the University of Michigan, Ann Arbor. "Because they tend to be at very large distances and surrounded by dusty envelopes, it's very hard to separate and closely observe them."

To get a better look, Kraus' team used the Very Large Telescope Interferometer of the European Southern Observatory in Chile to focus on IRAS 13481-6124, a star located at a distance of 10,000 light-years away in the constellation Centaurus, and about 20 times more massive than our sun. "We were able to get a very sharp view into the innermost regions around this star by combining the light of separate telescopes," Kraus said, "basically mimicking the resolving power of a telescope with an incredible 85-meter [280-foot] mirror."

The team's observations yielded a jackpot result: the discovery of a massive disk of dust and gas encircling the giant young star. "It's the first time something like this has been observed," Kraus said. "The disk very much resembles what we see around young stars that are much smaller, except everything is scaled up and more massive."

The presence of the disk is strong evidence that even the very largest stars in the galaxy form by the same process as smaller ones growing out of the dense accumulation of vast quantities of gas and dust, rather than the merging of smaller stars, as had been previously suggested by some scientists. The results were confirmed by NASA's Spitzer Space Telescope. "We looked at archival images of the star taken by Spitzer, and confirmed that the star is flinging disk material outward from its polar regions, just as we see with smaller stars and their dust disks," Kraus said.

Still, huge stars like IRAS 13481-6124 provide the building blocks for life to arise elsewhere in the universe. "High-mass stars are where heavy elements necessary for life are created, so they are of major importance," Kraus said "This discovery is a clearer picture than we've had before and allows us to understand them better."

Giant Antenna Propped up and Ready for Joint Replacement

Workers at NASA's Deep Space Network complex in Goldstone, Calif., have been making precise, laser-assisted measurements to ensure a flat surface for pouring new grout as part of a major renovation on the 70-meter-wide "Mars antenna." While officially dubbed Deep Space Station 14, the antenna picked up the Mars name from its first task: tracking NASA's Mariner 4 spacecraft, which had been lost by smaller antennas after its historic flyby of Mars.

This work represents the first time network engineers have redesigned and replaced the hydrostatic bearing assembly, which enables the antenna to rotate horizontally. To accomplish this, they lifted the entire rotating structure of the giant antenna for the first time.

The hydrostatic bearing assembly puts the weight of the antenna on three pads, which glide on a film of oil around a large steel ring. The ring measures about 24 meters in diameter and must be flat to work efficiently. After 44 years of near-constant use, the Mars antenna needed a kind of joint replacement, since the bearing assembly had become uneven.

Engineers and managers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., which manages the Deep Space Network for NASA, drew up plans for new runner segments, new sole plates below the runner segments, and an epoxy grout that is more impervious to oil. The thicker segments deform less when the antenna's pads pass over them, and allow for more tightly sealed joints.

Since beginning work in March, engineers and technicians have carefully lifted several million pounds of delicate scientific instruments about five millimeters and transferred the weight of the antenna to temporary supporting legs. They have removed the old steel runner and cement-based grout. They have also installed sole plates, which cover the grout and anchor the new runner. Over the past week, JPL engineers checked to make sure the sole plates were level, and workers poured the new epoxy grout underneath to hold them in place. Mixing and pouring the new grout occurred at night to ensure the work was completed within the tight temperature tolerances required to handle this material.

Over the next few weeks, the new, thicker steel runner segments will be installed. Work is on track to return the antenna to service on Nov. 1, 2010.

Ares I-X Completes a Successful Flight Test

NASA's Ares I-X test rocket lifted off Oct. 28, 2009, at 11:30 a.m. EDT from Kennedy Space Center in Florida for a two-minute powered flight. The flight test lasted about six minutes from its launch from the newly modified Launch Complex 39B until splashdown of the rocket's booster stage nearly 150 miles downrange.

The 327-foot-tall Ares I-X test vehicle produced 2.6 million pounds of thrust to accelerate the rocket to nearly 3 g's and Mach 4.76, just shy of hypersonic speed. It capped its easterly flight at a suborbital altitude of 150,000 feet after the separation of its first stage, a four-segment solid rocket booster.

Parachutes deployed for recovery of the booster and the solid rocket motor, which were recovered at sea and will be towed back to Florida by the booster recovery ship, Freedom Star, for later inspection. The simulated upper stage and Orion crew module, and the launch abort system will not be recovered.

The flight test is expected to provide NASA with an enormous amount of data that will be used to improve the design and safety of the next generation of American spaceflight vehicles, which could again take humans beyond low Earth orbit.

Microsoft and NASA Bring Mars Down to Earth Through the WorldWide Telescope

Today, Microsoft Research and NASA are providing an entirely new experience to users of the World Wide Telescope, which will allow visitors to interact with and explore our solar system like never before. Viewers can now take exclusive interactive tours of the red planet, hear directly from NASA scientists, and view and explore the most complete, highest-resolution coverage of Mars available.

Dan Fay, director of Microsoft Research’s Earth, Energy and Environment effort, works with scientists around the world to see how technology can help solve their research challenges. Since early 2009, he’s been working with NASA to bring imagery from the agency’s Mars and Moon missions to life, and to make their valuable volumes of information more accessible to the masses.

“We wanted to make it easier for people everywhere, as well as scientists, to access these unique and valuable images,” says Fay. “NASA had the images and they were open to new ways to share them. Through the WorldWide Telescope we were able to build a user interface at WWT|Mars that would allow people to take advantage of the great content they had.”

To create the new Mars experience in the WorldWide Telescope, Fay worked closely with Michael Broxton of the NASA Ames Research Center’s Intelligent Robotics Group . Broxton leads a team in the IRG informally called the Mapmakers, which applies computer vision and image processing to problems of cartography. Over the years, the Mapmakers have taken satellite images from Mars, the moon and elsewhere, and turned them into useful maps. Broxton says that getting the results of NASA’s work out to the public is an important part of his mission.

“NASA has a history of providing the public with access to our spacecraft imagery,” he says. “With projects like the WorldWide Telescope, we’re working to provide greater access so that future generations of scientists can discover space in their own way.”

Total Solar Eclipse

On Sunday, 2010 July 11, a total eclipse of the Sun is visible from within a narrow corridor that traverses Earth's southern Hemisphere. The path of the Moon's umbral shadow crosses the South Pacific Ocean where it makes no landfall except for Mangaia and Easter Island . The path of totality ends just after reaching southern Chile and Argentina. The Moon's penumbral shadow produces a partial eclipse visible from a much larger region covering the South Pacific and southern South America.

Though no live coverage of the eclipse is planned, the National Geographic Channel will broadcast a special edition of Naked Science, "Easter Island Eclipse" with video from the eclipse shot earlier in the day, at 11:00pm EST on Sunday evening. The show will be rebroadcast on July 15th at 10pm.

Mile-long chunk of ice cave off green glacier

NASA-funded researchers monitoring Greenland's Jakobshavn Isbrae glacier report that a 7 square kilometer of the glacier broke up on July 6 and 7, as shown in the image above. The calving front – where the ice sheet meets the ocean – retreated nearly 1.5 kilometers in one day and is now further inland than at any time previously observed. The chunk of lost ice is roughly one-eighth the size of Manhattan Island, New York.

Research teams led by Ian Howat of the Byrd Polar Research Center at Ohio State University and Paul Morin, director of the Antarctic Geospatial Information Center at the University of Minnesota have been monitoring satellite images for changes in the Greenland ice sheet and its outlet glaciers. While this week's breakup itself is not unusual, Howat noted, detecting it within hours and at such fine detail is a new phenomenon for scientists.

"While there have been ice breakouts of this magnitude from Jakonbshavn and other glaciers in the past, this event is unusual because it occurs on the heels of a warm winter that saw no sea ice form in the surrounding bay," said Thomas Wagner, cryospheric program scientist at NASA Headquarters. "While the exact relationship between these events is being determined, it lends credence to the theory that warming of the oceans is responsible for the ice loss observed throughout Greenland and Antarctica."

Scientists estimate that as much as 10 percent of all ice lost from Greenland is coming through Jakobshavn, which is also believed to be the single largest contributor to sea level rise in the northern hemisphere. Scientists are more concerned about losses from the south branch of the Jakobshavn, as the topography is flatter and lower than in the northern branch.

In addition to the remote sensing work, Howat, Morin, and other researchers have been funded by NASA and the National Science Foundation to plant GPS sensors, cameras, and other scientific equipment on top of the ice sheet to monitor changes and understand the fundamental workings of the ice. NASA also has been conducting twice-yearly airborne campaigns to the Arctic and Antarctic through the IceBridge program and measuring ice loss with the ICESat and GRACE satellites.

Glory spacecraft

The Glory spacecraft, set to launch in November of 2010, will study how the sun and airborne particles called aerosols affect Earth's climate.

Scientists have a thorough understanding of how greenhouse gases impact the energy budget, but the roles that two other critical elements of the climate system the sun's total solar irradiance and atmospheric aerosol particles play are somewhat less certain. The Glory mission, which contains two key scientific instruments, will improve understanding of both.

One of these instruments the Aerosol Polarimetery Sensor will offer scientists new measurements of aerosols, which can affect climate by either absorbing or reflecting light depending on their type. The unique instrument measures polarized light to make aerosol measurements and should thus help scientists distinguish between aerosols types, such as dust and black carbon, from space. The other instrument, the Total Irradiance Monitor , will continue a long-running record of the sun's brightness with unprecedented accuracy.

Results from both instruments will be used to fine tune global climate models and to help scientists predict how climate change will impact different regions of the planet. Glory will join a fleet of other Earth observing satellites known as the A-Train. It is scheduled to launch aboard a Taurus XL launch vehicle no earlier than November 22, 2010.

A Cool Look at a Lunar Crate

TMini-RF, a synthetic aperture radar on board NASA’s Lunar Reconnaissance Orbiter, recently imaged a potentially ice-rich crater near the north pole of the Moon. Located at 84°N, 157°W, this permanently shadowed crater, about 5 miles in diameter, lies on the floor of the larger, more degraded crater Rozhdestvensky . With no sunlight to warm the crater floor and walls, ice brought to the Moon by comets or formed through interactions with the solar wind could potentially collect here.

The crater was first identified as a region of interest during the Indian Chandrayaan-1 mission last year, when it was seen to exhibit unusual radar properties consistent with the presence of ice. But with a resolution 10 times better than the radar aboard the Chandrayaan-1 spacecraft, Mini-RF allows us to see details of the crater’s interior. In particular, the circular polarization ratio measures the polarization characteristics of the radar echoes, which give clues to the nature of the surface materials.

The inset figure shows a "same-sense" radar image of the crater next to a colorized CPR image of the crater. Red pixels have CPR values greater than 1.2. The CPR values inside the crater are almost all greater than 1, whereas the CPR values outside the crater are generally low . Regions with CPR greater than 1 are relatively rare in nature, but are commonly seen in regions with thick deposits of ice . They are also seen in rough, blocky ejecta around fresh, young craters, but in that occurrence, scientists also observe high CPR outside the crater rim.

This feature has high CPR inside its rim, but low CPR outside. The Mini-RF team plans to examine data from the other LRO instruments, particularly temperature and topographic measurements, to better characterize the environment and setting of these unusual features near the poles of the Moon.

NASA Satellite Spots Oil at Mississippi Delta Mouth

On May 24, 2010, the Advanced Spaceborne Thermal Emission and Reflection Radiometer instrument on NASA's Terra spacecraft captured this false-color, high-resolution view of the very tip of the Mississippi River delta. Ribbons and patches of oil that have leaked from the Deepwater Horizon well offshore appear silver against the light blue color of the adjacent water. Vegetation is red.

In the sunglint region of a satellite image-where the mirror-like reflection of the sun gets blurred into a wide, bright strip-any differences in the texture of the water surface are enhanced. Oil smoothes the water, making it a better "mirror." Oil-covered waters are very bright in this image, but, depending on the viewing conditions oil-covered water may look darker rather than brighter.

The relative brightness of the oil from place to place is not necessarily an indication of the amount of oil present. Any oil located near the precise spot where the sun's reflection would appear, if the surface of the Gulf were perfectly smooth and calm, is going to look very bright in these images. The cause of the dark patch of water in the upper left quadrant of the image is unknown. It may indicate the use of chemical dispersants, skimmers or booms, or it may be the result of natural differences in turbidity, salinity or organic matter in the coastal waters.