NASA, Microsoft Reveal Mars In Pictures

As Earth's closest neighbor and with an atmosphere more similar to Earth's than any other planet in the solar system, Mars has long been a subject of great interest to astronomers and the public. NASA began exploring Mars with unmanned spacecraft in the 1970s, and the space agency hopes to eventually send a human to the Red Planet. In March 2009, NASA and Microsoft partnered under a Space Act Agreement to make images of Mars and other planets available through Microsoft's WorldWide Telescope, an