Mars rover. Mars Pathfinder mosaic image of the robotic Sojourner rover vehicle on the surface of Mars by the large rock called Yogi". Sojourner used its Alpha-Proton X-Ray Spectrometer (APXS) to study the composition of "Yogi". Pathfinder's ramp is at lower centre. Sojourner's circular tracks are from its soil mechanics experiments. The rover weighs 9 kilogrammes & is powered by a solar panel. An operator on Earth decides Sojourner's destination, but the rover itself chooses the best way to get there. This image is part of a 360 degree panorama taken by the Imager for Mars Pathfinder (IMP) on the 8th, 9th & 10th Martian days spent on Mars since it landed on 4 July 1997."