Rovers are a common sight on Mars these days; two of them are trundling across the planet right now. But the first Mars rover arrived at the Red Planet 20 years ago today. In three months of operations it covered only about the length of a football field. But it provided new information on Martian history, and tested the technology that made it possible to build more-capable rovers later on.
Protected by a cocoon of airbags, Mars Pathfinder tumbled to a landing in Ares Vallis, a region where a mighty flood took place a couple of billion years ago. The petal-shaped lander soon opened up, then turned on its instruments. And it sent the Sojourner rover on its way.
Sojourner wasn’t much bigger than a microwave oven, but it was the first rover on any solar-system body other than Earth and the Moon. It carried cameras and an instrument for measuring the composition of rocks and soil. That experiment found evidence that the region had once been wet — not bone dry, as it is today.
The Pathfinder base also found evidence of water in the distant past. And it conducted extensive observations of the Martian weather. It measured temperatures from near freezing to more than a hundred degrees below zero, and found that the winds were fairly light, with occasional strong gusts.
The mission showed that it was possible to land and operate a rover on another planet — making it possible to build the much bigger rovers that are exploring Mars today.
Script by Damond Benningfield