The most conspicuous feature yet observed on Mars by Mariner 9 is the darkish spot located near the top of this picture. It has been tentatively identified as Nix Olympica, a curious ring-shaped feature photographed by Mariners 6 and 7 in 1969 and a point which radar indicates is one of the highest on Mars. One possible explanation suggests a high mountain or plateau which is being seen as it rises up through the bright dust surrounding the rest of the planet. The picture, one of a series of 31 recorded on the first tape-load during approach to Mars, was taken at 8:46 a.m. PST, November 11, 1971, at a range of about 408,000 miles. North is at the top.
Mariner 9 was the first spacecraft to orbit another planet. The spacecraft was designed to continue the atmospheric studies begun by Mariners 6 and 7, and to map over 70% of the Martian surface from the lowest altitude (1500 kilometers [900 miles]) and at the highest resolutions (1 kilometer per pixel to 100 meters per pixel) of any previous Mars mission.
Mariner 9 was launched on May 30, 1971 and arrived on November 14, 1971.
