The Phoenix lander's footpads are about the size of a dinner plate. One of three is shown at the right, covered with Martian soil after a successful soft landing on the Red Planet on May 25.

Looking for water on Mars, researchers using detectors on board the orbiting Mars Odyssey spacecraft have created this false-color global map of energetic neutrons from the otherwise Red Planet. What do neutrons have to do with water?

What's the magnetic field like in the center of our Milky Way Galaxy? To help find out, NASA's SOFIA -- an observatory flying in a modified 747 -- imaged the central region with...