On July 4, 1997, NASA's Mars Pathfinder spacecraft landed on Mars, the first spacecraft to do so since Vikings 1 and 2 in 1976. Pathfinder carried Sojourner, a small rover about the size of a microwave oven, that was used to explore the area surrounding the landing site. Sojourner carries a spectrometer that can analyze the chemical makeup of rocks and dust on Mars. In this image, Sojourner is studying a large boulder that has been nicknamed “Yogi.” Although Yogi appears to be quite red on one side and bluish on the other, this is believed to be an illusion caused by the lighting conditions on the rock. Sojourner analyzed the composition of several different rocks near its landing site. Some appear to have unexpectedly high amounts of the element silicon while others have high amounts of sulfur. However, these measurements will require further refinement and interpretation before final conclusions are made about the composition of these rocks.
This slide is actually a mosaic of many individual images. These images were taken using two different cameras in slightly different positions on the Pathfinder spacecraft. As a result, there are some places in the mosaic where the images do not align perfectly. At the bottom of the image is the ramp used by Sojourner to drive off Pathfinder. Portions of the airbags used to cushion the landing are also visible. In the rover tracks between the ramp and Sojourner, a thin white streak may represent a layer in the martian soil.
Mars Pathfinder image 81696