The iconic "Earthrise" photo taken by astronaut Bill Anders through a window on the Apollo 8 command module on Dec. 24, 1968. Bill Anders/NASA hide caption

itoggle caption Bill Anders/NASA

KABOOM! A NASA illustration of a gamma-ray burst. They occur, the space agency says, when "a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole. The black hole then drives jets of particles that drill all the way through the collapsing star." NASA.gov hide caption

itoggle caption NASA.gov

NASA's PhoneSat, a 4-by-4-inch CubeSat satellite, will use an Android smartphone as its motherboard. It was among the 29 satellites launched Tuesday from Wallops Island, Va. Another miniature satellite, developed by high school students, also was on board. Dominic Hart/AP hide caption

itoggle caption Dominic Hart/AP

NASA's MAVEN, short for Mars Atmosphere and Volatile Evolution, with a capital "N" in EvolutioN, atop a United Launch Alliance Atlas V rocket, lifts off from Cape Canaveral Air Force Station, on Monday. John Raoux/AP hide caption

itoggle caption John Raoux/AP

NASA's Lunar Atmosphere and Dust Environment Explorer probe, seen in this artist's rendering, is orbiting the moon to gather detailed information about the lunar surface. Dana Berry/NASA hide caption

itoggle caption Dana Berry/NASA

A photo composed of nearly 900 images taken by the rover Curiosity shows a section of Gale Crater near the equator of Mars. The rovers are continuing to work through the U.S. government shutdown. NASA/AP hide caption

itoggle caption NASA/AP