Sojourner. Mars Pathfinder mosaic image of the robotic Sojourner vehicle on the surface of Mars near the rock known as Barnacle Bill" (at centre left). "Barnacle Bill" was the first rock to be studied by Sojourner with its Alpha-Proton X-Ray Spectrometer (APXS). Sojourner also carries a high-resolution camera to study rocks. The rover weighs about 9 kilogrammes, is 63 centimetres (cm) long and 48cm wide. It is powered by a solar panel which will allow for a few hours movement per day, and is controlled by an operator on Earth. Image taken by the Imager for Mars Pathfinder (IMP) on the third Martian day (Sol 3) spent on Mars since it landed on 4 July 1997."