Mars: Past missions, major discoveries

Since 1960, dozens of spacecraft have been sent to Mars. It is difficult to send a spacecraft to Mars and even harder to land on the planet because of the thin atmosphere.

Data revealed the largest volcanoes in the solar system and one of the largest canyons yet discovered. Dust storms regularly sweep over the plains. Several spacecraft orbiting Mars shows an active planet rich in ingredients needed for life - water, organic carbon, and an energy source.