Nell GreenfieldboyceNell Greenfieldboyce is a NPR science correspondent.
An artist's rendition of two Sinosauropteryx dinosaurs, showing their short, bristle-like feathers along the midline of the head, neck, back and around the tail, forming irregular stripes.
Chuang Zhao and Lida Xing
In 2004, Comet C/2001 Q4 (NEAT), seen here, passed within 30 million miles of the Earth's orbit. A new report suggests that such near-Earth objects may go undetected by NASA, unless additional funding is provided.
Courtesy of NASA
Space Shuttle Discovery lands at Edwards Air Force Base on Sept. 11, 2009. Discovery has been promised to the Smithsonian, but NASA's other two shuttles, Endeavour and Atlantis, are still up for grabs.
A view of the central region of the Milky Way galaxy. Dark matter accounts for over 70% of the mass of the Milky Way, but because dark matter is invisible, all we see when we look up in the sky is a small amount of stars, planets and gas.
Our sense of time can be influenced by things like drinking coffee, or being on an adrenaline rush from an amusement park ride like this one at Dreamworld in Australia.
Bradley Kanaris/Getty Images