Giant Ultraviolet Rings Found in Resurrected Galaxies

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-264&cid=release_2010-264

Astronomers have found mysterious, giant loops of ultraviolet light in aged, massive galaxies, which seem to have a second lease on life. Somehow these "over-the-hill galaxies" have been infused with fresh gas to form new stars that power these truly gargantuan rings, some of which could encircle several Milky Way galaxies.

The discovery of these rings implies that bloated galaxies presumed "dead" and devoid of star-making can be reignited with star birth, and that galaxy evolution does not proceed straight from the cradle to the grave.

"In a galaxy's lifetime, it must make the transition from an active, star-forming galaxy to a quiescent galaxy that does not form stars," said Samir Salim, lead author of a recent study and a research scientist in the department of astronomy at Indiana University, Bloomington. "But it is possible this process goes the other way, too, and that old galaxies can be rejuvenated."

Nasa check for 'unlikely' survival of Mars lander

Nasa's Mars Odyssey orbiter is set to listen for possible radio transmissions from the Phoenix Mars lander, to check if it has survived the Martian winter.

The agency said that communication from the lander was "extremely unlikely".

Phoenix's last communication was on 2 November 2008, after it completed its study of an arctic Martian site.

Since then, this landing site has gone through autumn, winter and part of spring, and Phoenix was not designed to survive such temperature extremes.

Its electronics are likely to have broken up as temperatures plummeted.

But, just in case, Odyssey will pass over the Phoenix landing site approximately 10 times each day during three consecutive days of listening, beginning on 18 January.

It will undertake two longer "listening campaigns" in February and March.