Scientists say a brief burst of radio activity has been detected at the Arecibo radio telescope in Puerto Rico. This new report resembles previous activity detected in Australia, which has scientist debating possible causes, including solar flares, blitzars, or something even more mysterious. Brian Negin/iStockphoto hide caption

itoggle caption Brian Negin/iStockphoto

This composite image shows new details of the aftermath of a massive star that exploded and was visible from Earth over 1,000 years ago. Chandra X-ray Observatory Center/NASA hide caption

itoggle caption Chandra X-ray Observatory Center/NASA

An image showing the distribution of massive stars in the new study. Our location within the Galaxy is circled in black. J. Urquhart et al./Background image by Robert Hurt of the Spitzer Science Center. hide caption

itoggle caption J. Urquhart et al./Background image by Robert Hurt of the Spitzer Science Center.

An artist's impression of one of the super-Earth's surrounding the star Gliese 667 about 22 light years from Earth. ESO/L. Calçada hide caption

itoggle caption ESO/L. Calçada

An artist's impression of a gamma-ray burst, a powerful jet of energy lasting from less than a second to several minutes. The most powerful events in the universe, they are thought to be mostly associated with the explosion of stars that collapse into black holes. A. Roquette/ESO hide caption

itoggle caption A. Roquette/ESO

A composite of Lyrids over Huntsville, Ala., in 2009. This year, the meteor shower will hit its peak before dawn Sunday morning. Danielle Moser/MSFC/NASA hide caption

itoggle caption Danielle Moser/MSFC/NASA