Friday, January 29, 2010

Now a Stationary Research Platform, NASA's Mars Rover Spirit Starts a New Chapter in Red Planet Scientific Studies

view from the front hazard-avoidance camera on NASA's Mars Exploration
After six years of unprecedented exploration of the Red Planet, NASA's Mars Exploration Rover Spirit no longer will be a fully mobile robot. NASA has designated the once-roving scientific explorer a stationary science platform after efforts during the past several months to free it from a sand trap have been unsuccessful.

The venerable robot's primary task in the next few weeks will be to position itself to combat the severe Martian winter. If Spirit survives, it will continue conducting significant new science from its final location. The rover's mission could continue for several months to years.

"Spirit is not dead; it has just entered another phase of its long life," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. "We told the world last year that attempts to set the beloved robot free may not be successful. It looks like Spirit's current location on Mars will be its final resting place."

Ten months ago, as Spirit was driving south beside the western edge of a low plateau called Home Plate, its wheels broke through a crusty surface and churned into soft sand hidden underneath.

After Spirit became embedded, the rover team crafted plans for trying to get the six-wheeled vehicle free using its five functioning wheels – the sixth wheel quit working in 2006, limiting Spirit's mobility. The planning included experiments with a test rover in a sandbox at NASA's Jet Propulsion Laboratory in Pasadena, Calif., plus analysis, modeling and reviews. In November, another wheel quit working, making a difficult situation even worse.

Recent drives have yielded the best results since Spirit became embedded. However, the coming winter mandates a change in strategy. It is mid-autumn at the solar-powered robot's home on Mars. Winter will begin in May. Solar energy is declining and expected to become insufficient to power further driving by mid-February. The rover team plans to use those remaining potential drives for improving the rover's tilt. Spirit currently tilts slightly toward the south. The winter sun stays in the northern sky, so decreasing the southward tilt would boost the amount of sunshine on the rover's solar panels.

Monday, January 25, 2010

2009: Second Warmest Year on Record; End of Warmest Decade

10yrs avg global temperature index
2009 was tied for the second warmest year in the modern record, a new NASA analysis of global surface temperature shows. The analysis, conducted by the Goddard Institute for Space Studies (GISS) in New York City, also shows that in the Southern Hemisphere, 2009 was the warmest year since modern records began in 1880.

Although 2008 was the coolest year of the decade -- due to strong cooling of the tropical Pacific Ocean -- 2009 saw a return to near-record global temperatures. The past year was only a fraction of a degree cooler than 2005, the warmest year on record, and tied with a cluster of other years -- 1998, 2002, 2003, 2006 and 2007 -- as the second warmest year since recordkeeping began.

“There’s always an interest in the annual temperature numbers and on a given year’s ranking, but usually that misses the point,” said James Hansen, the director of GISS. “There's substantial year-to-year variability of global temperature caused by the tropical El Niño-La Niña cycle. But when we average temperature over five or ten years to minimize that variability, we find that global warming is continuing unabated."

January 2000 to December 2009 was the warmest decade on record. Throughout the last three decades, the GISS surface temperature record shows an upward trend of about 0.2°C (0.36°F) per decade. Since 1880, the year that modern scientific instrumentation became available to monitor temperatures precisely, a clear warming trend is present, though there was a leveling off between the 1940s and 1970s.

Thursday, January 21, 2010

Study Links Spring Ozone Over North America With Emissions Abroad

Lidar (light detection and ranging) beams from the tropospheric ozone lidar laboratory at JPL's Table Mountain Facility near Wrightwood, Calif., provided tropospheric ozone data used in the NOAA study
Springtime ozone levels above western North America are rising, primarily due to air flowing eastward from the Pacific Ocean, a trend that is most significant when the air originates in Asia. These increases in ozone could make it more difficult for the United States to meet Clean Air Act standards for ozone pollution at ground level, according to a new international study published online Jan. 20 in the journal Nature.

The study led by the National Oceanic and Atmospheric Administration (NOAA) analyzed large quantities of ozone data captured since 1984. Among the data sources for the study were profiles of ozone in Earth's troposphere (lowermost atmosphere) measured since 1999 by the differential absorption lidar (laser detection and ranging) system located at the NASA Jet Propulsion Laboratory Table Mountain Facility near Wrightwood, Calif. That remote, high-altitude facility enables research in atmospheric science, optical communication and astronomy. Measurements from atmospheric balloons launched from Table Mountain also contributed to the findings.

"In springtime, pollution from across the hemisphere, not nearby sources, contributes to the ozone increases above western North America," said lead author Owen R. Cooper of the NOAA-funded Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder. "When air is transported from a broad region of south and east Asia, the trend is largest."

The study focused on springtime ozone in a slice of the atmosphere from 3 to 8 kilometers (2 to 5 miles) above the surface of western North America, far below the protective ozone layer but above ozone-related, ground-level smog that is harmful to human health and crops. Ozone in this intermediate region constitutes the northern hemisphere background, or baseline level, of ozone in the lower atmosphere. The study was the first to pull together and then analyze the nearly 100,000 ozone observations gathered in separate studies by instruments on aircraft, balloons and other platforms.

Combustion of fossil fuels releases pollutants like nitrogen oxides and volatile organic compounds, which react in the presence of sunlight to form ozone. North American emissions contribute to global ozone levels, but the researchers did not find any evidence that these local emissions are driving the increasing trend in ozone above western North America.

Sunday, January 17, 2010

Port-Au-Prince, Haiti in January 2010

Haiti Image
NASA’s Earth Observing-1 satellite with the Advanced Land Imager (ALI) instrument aboard took an image centered on Port-au-Prince, Haiti on Friday, January 15, 2010, three days after the earthquake. The picture on the left is the entire ALI image. The lower right image is a zoom-in of Port-au-Prince, while the upper right image is the same view taken in September 2008, one week after Hurricane Ike. Significant features can be seen in both zoom images. Hurricane Ike unleashed torrential rains that caused severe flooding as depicted (upper right image) in the excessive discharge of sediment at the river delta, just north of downtown Port-au-Prince. The pier in the center of the 2008 image collapsed during the earthquake and is not visible in the 2010 image (lower right image).

Wednesday, January 13, 2010

Asteroid To Fly By Earth Wednesday Is a Natural

Asteroid 2010 AL30, discovered by the LINEAR survey of MIT's Lincoln Laboratories on Jan. 10, will make a close approach to the Earth's surface to within 76,000 miles on Jan. 13 at 12:46 pm Greenwich time (7:46 am EST, 4:46 am PST). Because its orbital period is nearly identical to the Earth's one year period, some have suggested it may be a manmade rocket stage in orbit about the sun. However, this object's orbit reaches the orbit of Venus at its closest point to the sun and nearly out to the orbit of Mars at its furthest point, crossing the Earth's orbit at a very steep angle. This makes it very unlikely that 2010 AL30 is a rocket stage. Furthermore, trajectory extrapolations show that this object cannot be associated with any recent launch and it has not made any close approaches to the Earth since well before the Space Age began.

It seems more likely that this is a near-Earth asteroid about 10-15 meters in size, one of approximately 2 million such objects in near-Earth space. One would expect a near-Earth asteroid of this size to pass within the moon's distance about once every week on average. The asteroid does not pose a risk, in fact, stony asteroids under 25 meters in diameter would be expected to burn up in our atmosphere, causing little or no ground damage.

Tuesday, January 12, 2010

Cassini Returns to Southern Hemisphere of Titan

Artist's concept of Cassini's Jan. 12, 2010NASA'S Cassini spacecraft will return to Titan's southern hemisphere on a flyby tomorrow, Jan. 12, plunging to within about 1,050 kilometers (about 670 miles) of the hazy moon's surface. During this pass, the onboard radar instrument will scan Ontario Lacus, the largest lake in the southern hemisphere, in a quest to learn more about the liquid methane and ethane in the lake and obtain more detailed topographical information about the shoreline. Titan is the only other body in the solar system besides Earth that is known to have stable liquid on its surface.

This will also be the most southern pass in the mission for the ion and neutral mass spectrometer instrument, which will probe the composition and density of the atmosphere near Titan's south pole. The atmospheric data collected on this pass will be paired with a similar sampling mission near Titan's north pole during the most recent flyby, 16 days earlier.

Cassini last flew by Titan on Dec. 27, 2009 California time, or Dec. 28 Universal Time. Although this latest flyby is dubbed "T65," planning changes early in the orbital tour have made this the 66th targeted flyby of Titan. This flyby also comes two days before the fifth anniversary of the landing of the Huygens probe on the surface of Titan.

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 Cassini mission for NASA's Science Mission Directorate, Washington, D.C. JPL designed, developed and assembled the Cassini orbiter. The Huygens probe, built and managed by the European Space Agency, was bolted to Cassini and rode along during its nearly seven-year journey to Saturn, before being released for its descent through Titan's atmosphere.

Monday, January 11, 2010

NASA Supports the President's Educate To Innovate Campaign With Summer Of Innovation To Bring Students The Universe

NASA has launched an initiative to use its out-of-this-world missions and technology programs to boost summer learning, particularly for underrepresented students across the nation. NASA's Summer of Innovation supports President Obama's Educate to Innovate campaign for excellence in science, technology, engineering and mathematics, or STEM, education.

The Summer of Innovation program will work with thousands of middle school teachers and students during multi-week programs in the summer of 2010 to engage students in stimulating math and science-based education programs. NASA's goal is to increase the number of future scientists, mathematicians, and engineers, with an emphasis on broadening participation of low-income, minority students.

"This is an incredible opportunity for our administration to come together to address our nation's critical science, technology, engineering and math education needs," said NASA Administrator and former astronaut Charles F. Bolden. "Through Summer of Innovation, NASA is calling on our financial and human resources to align with federal, state, and local governments, nonprofit partners, universities and teachers to expand the opportunity for more of our young people to aspire to and engage in the future prosperity of our nation."

Thursday, January 07, 2010

JPL Mourns Passing of Former Director Lew Allen Jr

JPL Director, AllenA former director of NASA's Jet Propulsion Laboratory, Lew Allen Jr., passed away Monday night, Jan. 4, at the age of 84, in Potomac Falls, Va. He led the laboratory from 1982 till 1990, during a period that included the launches of the Galileo mission to Jupiter, Magellan to Venus and the Infrared Astronomical Satellite, as well as Voyager 2's Uranus and Neptune flybys.

Allen was born Dec. 30, 1925, in Miami. He studied at the United States Military Academy at West Point, N.Y., and had a distinguished career in the U.S. Army and the Air Force, where he remained until 1982, achieving the rank of four-star general and serving as Chief of Staff of the Air Force.

In 1954, while still an Air Force officer assigned to the Los Alamos National Laboratory in New Mexico, Allen completed his doctorate in nuclear physics. He specialized in the potentially damaging effects of high-altitude nuclear explosions on the ground and on spacecraft.

After leaving Los Alamos in 1961, Allen served in various scientific posts within the Office of the Secretary of Defense and the Office of the Secretary of the Air Force. Allen became director of the National Security Agency in 1973. Allen was also a member of the National Academy of Engineering and the Council on Foreign Relations.

Wednesday, January 06, 2010

Sun Glints Seen from Space Signal Oceans and Lakes

A sun glint on Earth is captured (center of the black circle)In two new videos from NASA’s Deep Impact spacecraft, bright flashes of light known as sun glints act as beacons signaling large bodies of water on Earth. These observations give scientists a way to pick out planets beyond our solar system (extrasolar planets) that are likely to have expanses of liquid, and so stand a better chance of having life.

These sun glints are like sunshine glancing off the hood of a car. We can see them reflecting off a smooth surface when we are positioned in just the right way with respect to the sun and the smooth surface. On a planetary scale, only liquids and ice can form a surface smooth enough to produce the effect—land masses are too rough—and the surface must be very large. To stand out against a background of other radiation from a planet, the reflected light must be very bright. We won’t necessarily see glints from every distant planet that has liquids or ice.

But these sun glints are important because, if we saw an extrasolar planet which had glints that popped up periodically, we would know that we were seeing lakes, oceans or other large bodies of liquid, such as water,” says Drake Deming, of NASA’s Goddard Space Flight Center in Greenbelt, Md. Deming is the deputy principal investigator who leads the team that works on the Extrasolar Planet Observations and Characterization (EPOCh) part of Deep Impact’s extended mission, called EPOXI. “And if we found large bodies of water on a distant planet, we would become much more optimistic about finding life.”

One of EPOCh’s goals is to observe the Earth from far away—in this case, about 11 million miles away—so that we know what an Earth-like planet would look like when viewed from our spacecraft. The images in these videos were collected when the spacecraft was close enough to resolve some of Earth’s features, but at the same time, Earth could be treated as a very distant, single point. “This allows us to properly simulate what we would have observed if Earth were an extrasolar planet,” says Michael A’Hearn, principal investigator for EPOXI.

The researchers expected to see the sun glints but were surprised by the intensity and small focus of some, says Goddard’s Richard K. Barry. Glints appeared over oceans, most likely in relatively calm patches, and over a few land masses, probably caused by large inland lakes. Barry, who is leading the Earth-glint research effort, is putting together a catalog that will relate each glint to an exact location on Earth.

Together, the new videos provide the first view of Earth for a full rotation from the north pole (shown in one video) and south pole (the second video). The resolution is high enough to distinguish land masses, bodies of water and clouds. Each 16-second video is a compilation of a series of green, blue and near-infrared images taken every 15 minutes on a single day. Each is also the end product of months of planning, sophisticated data processing and analysis by the team.

Tuesday, January 05, 2010

Massive Black Hole Implicated in Stellar Destruction

New results from NASA's Chandra X-ray Observatory and the Magellan telescopes suggest that a dense stellar remnant has been ripped apart by a black hole a thousand times as massive as the Sun. If confirmed, this discovery would be a cosmic double play: it would be strong evidence for an intermediate mass black hole, which has been a hotly debated topic, and would mark the first time such a black hole has been caught tearing a star apart.

Composite image of a so-called ultraluminous X-ray source, or ULX
This scenario is based on Chandra observations, which revealed an unusually luminous source of X-rays in a dense cluster of old stars, and optical observations that showed a peculiar mix of elements associated with the X-ray emission. Taken together, a case can be made that the X-ray emission is produced by debris from a disrupted white dwarf star that is heated as it falls towards a massive black hole. The optical emission comes from debris further out that is illuminated by these X-rays.

The intensity of the X-ray emission places the source in the "ultraluminous X-ray source" or ULX category, meaning that it is more luminous than any known stellar X-ray source, but less luminous than the bright X-ray sources (active galactic nuclei) associated with supermassive black holes in the nuclei of galaxies. The nature of ULXs is a mystery, but one suggestion is that some ULXs are black holes with masses between about a hundred and several thousand times that of the Sun, a range intermediate between stellar-mass black holes and supermassive black holes located in the nuclei of galaxies.

Monday, January 04, 2010

NASA Image of Saturn Featured in Time Magazine's 'Year in Pictures'

A stunning view of Saturn from NASA's Cassini spacecraft has made Time Magazine's 2009 "Year in Pictures."

The photo, released in September and dubbed "The Rite of Spring," was the first up close view from a spacecraft from Earth of Saturn's equinox, when the sun's disk is directly overhead at Saturn's equator. That sun angle illuminates the gas giant's famous rings edge-on, opening up a new perspective.

Saturn image in Time magazine

As Cassini imaging team leader Carolyn Porco tells Time, "The geometry revealed structures and phenomena in the rings we had never seen before. We saw this famous adornment spring from two dimensions into three, with some ring structures soaring as high as the Rocky Mountains. It made me feel blessed."

The spectacle occurs twice during each orbit Saturn makes around the sun, which takes approximately 10,759 Earth days, or about 29.7 Earth years. Earth experiences a similar equinox phenomenon twice a year; the autumnal equinox will occur Sept. 22, when the sun will shine directly over Earth's equator.

For about a week, scientists used the Cassini orbiter to look at puffy parts of Saturn's rings caught in white glare from the low-angle lighting. Scientists have known about vertical clumps sticking out of the rings in a handful of places, but they could not directly measure the height and breadth of the undulations and ridges until Saturn's equinox revealed their shadows.