Wednesday, December 30, 2009

Suzaku Finds "Fossil" Fireballs from Supernovae

In the supernova remnant W49B, Suzaku found another fossil fireball. It detected X-rays produced when heavily ionized iron atoms recapture an electron. This view combines infrared images from the ground (red, green) with X-ray data from NASA's Chandra X-Ray Observatory.

Monday, December 28, 2009

Cassini Spacecraft to Monitor North Pole on Titan

Though there are no plans to investigate whether Saturn's moon Titan has a Santa Claus, NASA's Cassini will zoom close to Titan's north pole this weekend.

The flyby, which brings Cassini to within about 960 kilometers (600 miles) of the Titan surface at 82 degrees north latitude, will take place the evening of Dec. 27 Pacific time, or shortly after midnight Universal Time on Dec. 28.

The encounter will enable scientists to gather more detail on how the lake-dotted north polar region of Titan changes with the seasons. Scientists will be using high-resolution radar to scan the large and numerous lakes in the north polar region for shape-shifting in size and depth. The ion and neutral mass spectrometer team will take baseline measurements of the atmosphere to compare with the moon's south polar region when Cassini flies by that area on Jan. 12. Cassini will also be collecting images for a mosaic of a bright region called Adiri, where the Huygens probe landed nearly five years ago.

Thursday, December 24, 2009

Right-Front and Right-Rear Wheels Sit Out Latest Drive

Spirit's drive on Sol 2120 included commands for using all six wheels. However, the right-front wheel rotated less than 2 degrees and the right-rear wheel did not rotate at all. The other four wheels completed enough rotations to drive about 10 meters (33 feet), but produced no measurable forward motion by the rover.

The rover team plans to command further driving this week while continuing to assess the possibility of getting more motion from the right-front wheel.

Wednesday, December 23, 2009

Mayon Volcano, The Phillipines

Tens of thousands of people living within the danger zone of Mayon Volcano in the Philippines were forced to evacuate to emergency shelters in mid-December 2009 as small earthquakes, incandescent lava at the summit and minor ash falls suggested a major eruption was on the way. On the evening of Dec. 14, the local volcano observatory raised the alert level to Level 3, which means "magma is close to the crater and hazardous explosive eruption is imminent."

This natural-color image of Mayon was captured on Dec. 15, 2009, by the Advanced Land Imager on NASA's Earth Observing-1 (EO-1) satellite. A small plume of ash and steam is blowing west from the summit. Dark-colored lava or debris flows from previous eruptions streak the flanks of the mountain. A ravine on the southeast slope is occupied by a particularly prominent lava or debris flow.

The Phillipine Star said on Dec. 22 that "ashfall blanketed at least three towns in Albay, raising new health fears for thousands already bracing for an eruption that could come at any time ... Health officials warned the tiny particles could cause respiratory problems or skin diseases, and could affect the thousands of people crammed into evacuation centers.

Also on Dec. 22, CNN reported that "tens of thousands of people have already fled their homes. More than 9,000 families -- a total of 44,394 people -- are being housed in evacuation camps after authorities raised the alert status of the country's most active volcano" as "fountains of red-hot lava shot up from the intensifying Mayon volcano."

Tuesday, December 22, 2009

Terra Turns Ten: Snow, Clouds and Sunlight

NASA flies three large, multi-sensor satellites that monitor Earth’s land, atmosphere, oceans and energy balance. Because the instruments on each satellite take measurements at the same time from the same vantage point, scientists are able to compare observations and tease out connections between different parts of the Earth system. The first of the three satellites, Terra, launched ten years ago on Dec. 18, 1999. In the decade since Terra launched, scientists have gained insight into the intricate connections that shape our planet's climate. The relationship between snow, clouds, and sunlight is a good example.

In November, the chill and snow of a Northern Hemisphere winter is on the horizon. Snow covers the far north and high elevations, as shown in the map of percent snow cover in November 2009. White areas show where snow covers the ground completely, while blue points to areas with partial snow cover. At the peak of the northern winter, more than 40 percent of the Earth’s land will be covered in snow.

In addition to being an important, life-sustaining source of water, the snow also reflects sunlight, limiting the amount of heat the Earth absorbs from the sun.

Monday, December 21, 2009

AcrimSat Celebrates 10 Years of Measuring the Sun's Energy

Launched Dec. 20, 1999, the Active Cavity Radiometer Irradiance Monitor Satellite (AcrimSat) monitors the total amount of the sun's energy reaching Earth. It is this energy, called total solar irradiance, that creates the winds, heats the land and drives ocean currents.

Some scientists theorize a significant fraction of Earth's warming may be solar in origin due to small increases in the sun's total energy output since the last century. By measuring incoming solar radiation, climatologists are using AcrimSat to improve their predictions of climate change and global warming over the next century.

Saturday, December 19, 2009

New Cool Stars

Astronomers think there are roughly as many brown dwarfs as regular stars like our sun, but brown dwarfs are often too cool to find using visible light. These tiny orbs are similar to stars but they are cooler and less massive. They lack the mass to fuse atoms at their cores and shine with starlight. Using infrared light, NASA's Wide-field Infrared Survey Explorer (WISE), will find many dozens of brown dwarfs within 25 light years of the sun.

These two pictures show simulated data before and after the WISE mission (stars are not real). The simulated picture on the left shows known stars (white and yellow) and brown dwarfs (red) in our solar neighborhood. The picture on the right shows additional brown dwarfs WISE is expected to find. One of these newfound brown dwarfs could even be closer to us than our closest known star, Proxima Centauri, which is four light-years away.

Friday, December 18, 2009

Reflection of Sunlight off Titan Lake

This image shows the first flash of sunlight reflected off a lake on Saturn's moon Titan. The glint off a mirror-like surface is known as a specular reflection. This kind of glint was detected by the visual and infrared mapping spectrometer (VIMS) on NASA's Cassini spacecraft on July 8, 2009. It confirmed the presence of liquid in the moon's northern hemisphere, where lakes are more numerous and larger than those in the southern hemisphere. Scientists using VIMS had confirmed the presence of liquid in Ontario Lacus, the largest lake in the southern hemisphere, in 2008.

The northern hemisphere was shrouded in darkness for nearly 15 years, but the sun began to illuminate the area again as it approached its spring equinox in August 2009. VIMS was able to detect the glint as the viewing geometry changed. Titan's hazy atmosphere also scatters and absorbs many wavelengths of light, including most of the visible light spectrum. But the VIMS instrument enabled scientists to look for the glint in infrared wavelengths that were able to penetrate through the moon's atmosphere. This image was created using wavelengths of light in the 5 micron range.

Thursday, December 17, 2009

Quiet Sun Means Cooling of Earth's Upper Atmosphere

Data from the TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) mission are being used to understand the climate of the upper atmosphere

New measurements from a NASA satellite show a dramatic cooling in the upper atmosphere that correlates with the declining phase of the current solar cycle. For the first time, researchers can show a timely link between the Sun and the climate of Earth’s thermosphere, the region above 100 km, an essential step in making accurate predictions of climate change in the high atmosphere.

Scientists from NASA's Langley Research Center and Hampton University in Hampton, Va., and the National Center for Atmospheric Research in Boulder, Colo., presented these results at the fall meeting of the American Geophysical Union in San Francisco from Dec. 14 to 18.

Wednesday, December 16, 2009

Hubble's Festive View of a Grand Star-Forming Region

Just in time for the holidays: a Hubble Space Telescope picture postcard of hundreds of brilliant blue stars wreathed by warm, glowing clouds. The festive portrait is the most detailed view of the largest stellar nursery in our local galactic neighborhood.

The massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. There is no known star-forming region in our galaxy as large or as prolific as 30 Doradus.

Many of the diamond-like icy blue stars are among the most massive stars known. Several of them are over 100 times more massive than our Sun. These hefty stars are destined to pop off, like a string of firecrackers, as supernovas in a few million years.

Tuesday, December 15, 2009

Lifting Off to Study the Sky

NASA's Wide-field Infrared Survey Explorer, or WISE, launched aboard a United Launch Alliance Delta II rocket at 9:09 a.m. EST from Space Launch Complex-2...

Friday, December 11, 2009

Magnetic Dance of Titan and Saturn To Be Main Attraction during Flyby

Artist's concept of Cassini's Dec. 11, 2009, flyby of Saturn's largest moon, Titan.

When it flies by Saturn's largest moon, Titan, this weekend, NASA's Cassini spacecraft will study the interactions between the magnetic field of Saturn and Titan. The flyby will take place the evening of Dec. 11 California time, or shortly after midnight Universal Time on Dec. 12.

As Titan plows through the magnetic bubble, or magnetosphere around Saturn, it creates a wake in the magnetic field lines coming away from the planet. This flyby will allow Cassini's fields and particles instruments to study that wake about 5,200 kilometers (3,200 miles) away from the moon, a relatively unexamined region. Other instruments will also be taking a closer look at Titan's clouds.

At closest approach to Titan, Cassini will swing to within about 4,900 kilometers (3,000 miles) of the surface of the moon.

Cassini last zoomed by Titan two months ago. Although this latest flyby is dubbed "T63," planning changes early in the orbital tour have made this the sixty-fourth targeted flyby of Titan.

Titan is a kind of "sister world" to Earth because it has a surface covered with organic material and an atmosphere whose chemical composition hearkens back to an early Earth.

Thursday, December 10, 2009

Fermi Sees Brightest-Ever Blazar Flare

A galaxy located billions of light-years away is commanding the attention of NASA's Fermi Gamma-ray Space Telescope and astronomers around the globe. Thanks to a series of flares that began September 15, the galaxy is now the brightest source in the gamma-ray sky -- more than ten times brighter than it was in the summer.

Astronomers identify the object as 3C 454.3, an active galaxy located 7.2 billion light-years away in the constellation Pegasus. But even among active galaxies, it's exceptional.

"We're looking right down the barrel of a particle jet powered by the galaxy's supermassive black hole," said Gino Tosti at the National Institute of Nuclear Physics in Perugia, Italy. "Some change within that jet -- we don't know what -- is likely responsible for these flares."

Wednesday, December 09, 2009

Space Station Laboratory Racks Interactive

The International Space Station hosts astronauts, gear and science from around the world. Three laboratories from Europe, Japan and the United States bring them all together for the most advanced research and development. More than 150 experiments involving researchers from around the world are active at any given time.

While the space station is the most advanced spacecraft ever built, its coordinate system is labeled like any sea-faring vessel on Earth using traditional nautical terms. Understanding this coordinate system will help you use this interactive and understand the relative positions of the onboard experiment facilities.

The orbiting laboratory’s left and right sides are designated as port and starboard respectively. The rear of the station is the aft section where the Russian Zvezda service module is located. The front of the station, where the U.S. Harmony module is located, is labeled the forward section. The side of the station facing the Earth is the deck and the opposite side is the overhead

Tuesday, December 08, 2009

Universe Unveils Never-Before-Seen Galaxies

NASA's Hubble Space Telescope has made the deepest image of the universe ever taken in near-infrared light. The faintest and reddest objects in the image are galaxies that formed 600 million years after the Big Bang. No galaxies have been seen before at such early times. The new deep view also provides insights into how galaxies grew in their formative years early in the universe's history.

The image was taken in the same region as the Hubble Ultra Deep Field (HUDF), which was taken in 2004 and is the deepest visible-light image of the universe. Hubble's newly installed Wide Field Camera 3 (WFC3) collects light from near-infrared wavelengths and therefore looks even deeper into the universe, because the light from very distant galaxies is stretched out of the ultraviolet and visible regions of the spectrum into near-infrared wavelengths by the expansion of the universe.

This image was taken by the HUDF09 team, that was awarded the time for the observation and made it available for research by astronomers worldwide. In just three months, 12 scientific papers have already been submitted on these new data.

The photo was taken with the new WFC3/IR camera on Hubble in late August 2009 during a total of four days of pointing for 173,000 seconds of total exposure time. Infrared light is invisible and therefore does not have colors that can be perceived by the human eye. The colors in the image are assigned comparatively short, medium, and long, near-IR wavelengths (blue, 1.05 microns; green, 1.25 microns; red, 1.6 microns). The representation is "natural" in that blue objects look blue and red objects look red. The faintest objects are about one billionth as bright as can be seen with the naked eye.

Friday, December 04, 2009

Hitch A Ride On The Glory Satellite

Want to hitch a ride on NASA's next climate monitoring satellite? Join the Glory mission, which will launch no earlier than Oct. 1, by surfing over to the Send Your Name Around the Earth web page. Names will be recorded on a microchip built into the satellite, and you will get a printable certificate from NASA acknowledging your participation. There are already 225,155 names on the chip, but there's plenty more room.

Glory carries two scientific sensors dedicated to understanding the effects of aerosols and the sun's variability on Earth's climate. The Aerosol Polarimetry Sensor will collect information about tiny liquid and solid particles suspended in the atmosphere that absorb or reflect sunlight. The Total Irradiance Monitor will measure the intensity of incoming sunlight which can vary over time.

Thursday, December 03, 2009

Suzaku Spies Treasure Trove of Intergalactic Metal

Most of the ingredients are hydrogen and helium. These cosmic lightweights fill the first two spots on the famous periodic table of the elements.

The Perseus galaxy cluster contains 190 galaxies and lies about 225 million light-years away.

This Hubble Space Telescope image shows NGC 1275, a galaxy located in the center of the Perseus cluster. The red threadlike filaments are composed of cool gas suspended by a magnetic field
This image from the Japanese Advanced Satellite for Cosmology and Astrophysics shows the X-ray glow of the 100-million-degree Fahrenheit gas that fills the Perseus cluster. The white box indicates the area explored by the Suzaku X-ray telescope to detect chromium and manganese. The image is about two degrees wide, or four times the apparent width of a full moon.

Wednesday, December 02, 2009

Another Stall of Right-Rear Wheel Ends Drive

Spirit's right-rear wheel stalled again on Sol 2099 (Nov. 28, 2009) during the first step of a two-step extrication maneuver. This stall is different in some characteristics from the stall on Sol 2092 (Nov. 21). The Sol 2099 stall occurred more quickly and the inferred rotor resistance was elevated at the end of the stall.

Investigation of past stall events along with these characteristics suggest that this stall might not be result of the terrain, but might be internal to the right-rear wheel actuator. Rover project engineers are developing a series of diagnostics to explore the actuator health and to isolate potential terrain interactions. These diagnostics are not likely to be ready before Wednesday. Plans for future driving will depend on the results of the diagnostic tests.

Before the Sol 2099 drive ended, Spirit completed 1.4 meters of wheel spin and the rover's center moved 0.5 millimeters (0.02 inch) forward, 0.25 millimeters (0.01 inch) to the left and 0.5 millimeters (0.02 inch) downward. Since Spirit began extrication on Sol 2088, the rover has performed 9.5 meters (31 feet) of wheel spin and the rover's center, in total, has moved 16 millimeters (0.63 inch) forward, 10 millimeters (0.39 inch) to the left and 5 millimeters (0.20 inch) downward.

Tuesday, December 01, 2009

one-half of the nose cone

WISE is shown inside one-half of the nose cone, or fairing, that will protect it during launch. The spacecraft is clamped to the top of the rocket above the white conical fitting. The fairing will split open like a clamshell about five minutes after launch.

NASA's Wide-field Infrared Survey Explorer has been wrapped in the outer nose cone, or "fairing," that will protect it during its scheduled Dec. 9 launch from Vandenberg Air Force Base, Calif.

The fairing will split open like a clamshell about five minutes after launch. The spacecraft will circle Earth over the poles, scanning the entire sky one-and-a-half times in nine months. The mission will uncover hidden cosmic objects, including the coolest stars, dark asteroids and the most luminous galaxies.