Biggest, deepest crater exposes hidden, ancient Moon
Tue Mar 9, 2010 at 23:20 UTC
Shortly after the Moon formed, an asteroid smacked into its southern hemisphere and gouged out a truly enormous crater, the South Pole-Aitken basin, almost 1,500 miles across and more than five miles deep.
"This is the biggest, deepest crater on the Moon -- an abyss that could engulf the United States from the East Coast through Texas," said Noah Petro of NASA's Goddard Space Flight Center in Greenbelt, Md. The impact punched into the layers of the lunar crust, scattering that material across the Moon and into space. The tremendous heat of the impact also melted part of the floor of the crater, turning it into a sea of molten rock.

Planetary scientists have been puzzling for years over the honeycomb patterns and flat valleys with squiggly edges evident in radar images of Saturn's moon Titan.
Flowing lava can carve or build paths very much like the riverbeds and canyons etched by water, and this probably explains at least one of the meandering channels on the surface of Mars.
Keeping an infrared telescope at very cold operating temperatures isn't an option, it's an absolute necessity. For the James Webb Space Telescope to see the traces of infrared light generated by stars and galaxies billions of light years away, it must be kept at cryogenic temperatures of under 50 Kelvin (-370°F).
ESA's Herschel Space Observatory has revealed the chemical fingerprints of potential life-enabling organic molecules in the Orion Nebula, a nearby stellar nursery in our Milky Way galaxy.
New studies of ripples and dunes shaped by the winds on Mars testify to variability on that planet, identifying at least one place where ripples are actively migrating and another where the ripples have been stationary for 100,000 years or more.
In general, galaxies can be thought of as "social" -- hanging out in groups and frequently interacting.
New observations from NASA's Chandra X-ray Observatory provide evidence for powerful winds blowing away from the vicinity of a supermassive black hole in a nearby galaxy. This discovery indicates that "average" supermassive black holes may play an important role in the evolution of the galaxies in which they reside.
NASA's newest Mars orbiter, completing its fourth year at the Red Planet this week, has just passed a data-volume milestone unimaginable a generation ago and still difficult to fathom: 100 terabits.
Extensive radar mapping of the middle-latitude region of northern Mars shows that thick masses of buried ice are quite common beneath protective coverings of rubble.
One of the pleasures of perusing ancient maps is locating regions so poorly explored that mapmakers warned of dragons and sea monsters. Now, astronomers using NASA's Fermi Gamma-ray Space Telescope find themselves in the same situation as cartographers of old.
Using data from a NASA radar that flew aboard India's Chandrayaan-1 spacecraft, scientists have detected ice deposits near the moon's north pole. NASA's Mini-SAR instrument, a lightweight, synthetic aperture radar, found more than 40 small craters with water ice.
NASA's Phoenix Mars Lander showed no sign during February that it has revived itself after the northern Mars winter. NASA's Mars Odyssey orbiter will check again in early April.
The following new captioned and spotlight images taken by the High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter spacecraft are now available:
The following new images taken by the Imaging Science Subsystem (ISS) on the Cassini spacecraft are now available:

