This stereo pair of Hale-Bopp images combines two pictures from slightly different viewing angles. Simulating stereo vision, the difference was generated by the comet's apparent motion as it cruised through the inner Solar System.

On July 20, 1976, NASA's Viking 1 lander become the first spacecraft to land on Mars, followed weeks later by its twin robot explorer, the Viking 2 lander. Operating on the Martian surface...