follow Tommie on twitter

Thursday, January 08, 2009

Tommie's Science Corner: Mysterious Roar From Space

(story fr., Galactus from Some Dude's Blog)

Mystery Roar from Faraway Space Detected

No one's sure what causes it, but a team of astronomers has found a strange cosmic noise that booms six times louder than expected. The roar is from the distant cosmos.

Of course, sound waves can't travel in a vacuum (which is what most of space is), or at least they can't very efficiently. But radio waves can.

Radio waves are not sound waves, but they are still electromagnetic waves, situated on the low-frequency end of the light spectrum. Many objects in the universe, including stars and quasars, emit radio waves. Even our home galaxy, the Milky Way, emits a static hiss (first detected in 1931 by physicist Karl Jansky). Other galaxies also send out a background radio hiss.

But the newly detected signal, described here today at the 213th meeting of the American Astronomical Society, is far louder than astronomers expected.

They were initially looking for the faint hiss and heat measurements of some of the oldest stars, and were instead greeted by this loud roar from somewhere deep in space. Other radio galaxies also can't account for the noise – because there just aren't enough of them.

"We really don't know what it is,"said team member Michael Seiffert of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This is what makes science so exciting. You start out on a path to measure something – in this case, the heat from the very first stars – but run into something else entirely, some unexplained."

Team Leader Alan Kogut of NASA's Goddard Space Flight Center in Greenbelt, Md. had the best comment: "The universe really threw us a curve," Kogut said. "Instead of the faint signal we hoped to find, here was this booming noise six times louder than anyone had predicted."