Wednesday, December 30, 2009
Monday, December 28, 2009
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
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
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
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
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
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
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
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
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
Friday, December 11, 2009
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
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
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
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
Thursday, December 03, 2009
Wednesday, December 02, 2009
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
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.