Relatively short arms of gas and dust lend a woolly appearance to the flocculent spiral galaxy known as NGC 2841 in a new picture released last week taken by the NASA/ESA Hubble Space Telescope.
The galaxy lies about 46 million light-years away in the constellation Ursa Major, the Great Bear. NGC 2841 is unusual because its tightly curled arms display a relatively low rate of star formation compared with other spiral galaxies.
Image courtesy ESA/NASA
Combined x-ray and optical data lend a kaleidoscope of colors to the supernova remnant Cassiopeia A in a picture released to illustrate a new study of the famous object.
At the heart of Cas A is a neutron star (inset illustration), the ultradense core of a massive star that exploded. The new study, conducted with NASA's Chandra X-ray Observatory, found that a strange form of matter called a superfluid exists inside the neutron star.
Eddies of silvery sea ice drape around the snow-covered island of Shikotan, part of the Kuril chain (map) that stretches from northern Japan to Russia's Kamchatka Peninsula.
Shikotan lies along the southernmost border of winter sea ice cover in the Northern Hemisphere. Seen by NASA's Earth Observing-1 satellite on February 14, this sea ice likely formed quickly—within a matter of days—and was sculpted by opposing winds flowing around the small volcanic island.
While most eyes are on the launch of Discovery this week, NASA employees are busy preparing for the final two shuttle missions before the fleet of U.S. orbiters is retired later this year. After Discovery, the space shuttle Endeavour is slated to lift off in April.
Although still awaiting final funding approval from Congress, NASA is moving forward with the STS-135 mission, which will likely see Atlantis make the very last shuttle trip to the International Space Station in June.
The darker region at the top of the image is the flat surface of the plains surrounding the crater, which angles away from the camera. The lunar surface appears to become brighter as the wall of the crater slopes downward and reflects light directly toward LRO.
Even in this brighter region, though, pitch-black material seems to ooze from random points along the crater wall. Different minerals reflect light in different ways, and NASA scientists suspect these odd deposits may be traces of volcanic debris from ancient, explosive eruptions.
Image courtesy ASU/NASA
Thin Gray Line
Seen edge-on by NASA's Cassini orbiter, the rings of Saturn trace an incredibly thin line against the massive gas giant planet. But the picture, taken in January and released this week, also reveals the rings' true nature: The wide bands of icy particles cast broad shadows on the planet's southern hemisphere.
In 2009 Saturn was at equinox, when the sun was shining edge-on to the ring plane. During this time the rings didn't cast such shadows, and they seemed to vanish when viewed edge-on. (Related blog entry: "Saturn's Equinox Arrives.")