The historical space project yielded a tremendous amount of data—even more than scientists had planned or hoped—about the planet, totally reshaping many long-held notions about Mars, the fourth planet in the solar system. Pathfinder landed on Mars on July 4, 1997, and deployed a two-foot-long robotic rover called Sojourner. The small rover collected what project scientists described as a staggering amount of data: 2.3 billion bits of information about the planet; 8.5 million measurements of temperature and pressure; 16 chemical analyses of rocks, soil, and other surface materials; and 16,500 pictures. Among other things, the new data caused scientists to rethink the planet’s color: long believed to be red, the color is now described as a deep amber or butterscotch. The evidence gathered by Sojourner supports the notion that there may have been life on Mars. Future projects aimed at studying the planet’s properties will further explore the theory that there was once life on Mars. With the success of Pathfinder, project scientists turn their attention to improving the data-gathering capabilities of future rovers—including the addition of brushes to the robot, so that dust can be collected from rocks on the surface of Mars, which is a distance of 155 million miles from Earth.