Explorations by Robots
Before any human is to explore the red planet, rovers are sent to explore it first. After many attempts by the Russians and Americans to land on Mars failed due to the rocky surface or an error in the machine. Finally Viking 1 and Viking 2 landed successfully on the surface in 1976.
Viking 1 took two television cameras which made 26,000 photos of Mars and the Martian moons. It worked for 6 and a half years. It had a weather station, a seismometer, and soil analyzer but the seisometer failed. Viking 1 gave us much information about Mars such as information on the terrain, the composition and structure of the Martian atmosphere, etc. Viking 2 worked for 3 and a half years on Mars. It was equiped with the same equiptment as Viking 1 and managed to get similar information about Mars. Because of the Vikings we understand Mars better.
Seen above is the Sojourner rover. It landed on Mars in July 1997. It rolled around the planet's surface analyzing bits of rock and soil. Eventually communications with Earth were cut off because of failing power so the robot only lasted until September.
The rover currently on Mars is Spirit. It landed at Gusev crater in early January 2004. The Opportunity rover, Spirit's robot companion, landed on Mars a few weeks after Spirit did and is currently scouting the other side of Mars. The Opportunity rover and Spirit have discovered many mysterious things that have puzzled scientists. For example, the Opportunity rover discovered "blueberries" in the Meridani Planum area. "Blueberries" are tiny gray spheres of hematite. This could've been proof that water once infused the Meridani Planum area. Scientists wondered if these blueberries were the same everywhere or whether they change from place to place.