Month: December 2011

Stll Boldly Going: Voyager 1 and 2 See What No Man Has Seen Before

Speeding toward interstellar space, NASA’s twin Voyager probes have now truly peered outside the solar system—and they’ve seen something no human has glimpsed before.

According to a new study, the two spacecraft have detected a type of ultraviolet light from other regions of our Milky Way galaxy that had previously been all but invisible due to the sun’s glow.

“People have tried to make this measurement from Earth orbit, unsuccessfully,” said veteran Voyager scientist Bill Sandel of the University of Arizona in Tucson.

The light, a wavelength of ultraviolet called Lyman-alpha radiation, is emitted by hydrogen atoms as they cool down. The radiation is especially intense in stellar nurseries where lots of new stars are forming.

Read the rest of my story at National Geographic News.

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Faster-than-Light Galaxies and the Cosmic Magnifying Lens

My two latest posts at Degrees of Freedom describe how the universe acts as a giant magnifying lens, so that very distant galaxies appear larger in the sky than closer ones, in a reversal of the usual laws of perspective.

The Cosmic Magnifying Lens describes the phenomenon (check out the videos!), and

A Step-by-Step Guide to Cosmology’s Best-Kept Secret explains the physics behind it, which has to do with stuff receding from us faster than the speed of light. Because of the expansion of the universe, distant objects can indeed be superluminal.