News tagged with light signal

City lights could reveal E.T. civilization

In the search for extraterrestrial intelligence, astronomers have hunted for radio signals and ultra-short laser pulses. In a new paper, Avi Loeb (Harvard-Smithsonian Center for Astrophysics) and Edwin Turner ...

Nov 03, 2011
4.6 / 5 (29) 54 | with audio podcast

Ghost remains after black hole eruption

NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence ...

May 28, 2009
4.8 / 5 (17) 15