This image was acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) on August 20, 1997, when MGS was 5.51 million kilometers (3.42 million miles) and 22 days from encounter. At this distance, the MOC's resolution is about 20.6 km per picture element, and the 6800 km (4200 mile) diameter planet is about 330 pixels across. North is at the top of the image. The MGS spacecraft pointed the camera at the center of the planet (near the dark, morning sunrise line, or terminator) at 23.6° N, 307.3° W. The irregularity of the terminator seen in this image results from contrast processing. This image shows the prominent dark feature Syrtis Major, believed to be a relatively dust-free area of bedrock outcrop and sand dunes. The large Hellas impact basin (2000 km or 1250 miles across) is seen at the bottom of the picture. Clouds from the south polar region fill the basin. The north polar residual ice cap, surrounded by a dark annulus of sand, is seen at the top of the picture.
Launched on November 7, 1996, Mars Global Surveyor will enter Mars orbit on Thursday, September 11 around 6:30 PM PDT. After Mars Orbit Insertion, the spacecraft will use atmospheric drag to reduce the size of its orbit, achieving a circular orbit only 400 km (248 mi) above the surface in March 1998, when mapping operations will begin. At that time, MOC narrow angle images will be 14,000 times higher resolution than this picture, and global wide angle images will be 3 times better.
Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.