Many aspects of our studies of Mars from Earth are dictated by the different rates at which the two planets orbit the Sun. This difference allows Earth to pass Mars in its orbit, continue to lead Mars around the Sun, and then eventually overtake Mars again, every 26 months. This cycle governs opportunities to send rockets to Mars when the closest approaches between the two planets occur (opposition). The cycle also dictates when Mars will pass behind the Sun relative to Earth (conjunction).

A Solar Conjunction period has just ended. During this time radio communications from the Mars Global Surveyor spacecraft, operating at Mars, were interrupted for a few weeks. Because it would not be able to send pictures back to Earth during this time, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was turned off on June 21, 2000, and turned back on again July 13, 2000. The two pictures shown here are among the very first high resolution views of the martain surface that were received following the resumed operation of the MOC. Both pictures arrived on Earth via radio downlink on Saturday, July 15, 2000.

Hesperia Planum. Photo: Courtesy NASA/JPL/Malin Space Science Systems

The first picture (above) shows a ridged and cratered plain in southern Hesperia Planum around 32.8 degrees S, 243.2 degrees W. The second image (below) shows the layered northeastern wall of a meteor impact crater in Noachis Terra at 32.9 degrees S, 357.6 degrees W. Both pictures cover an area 3 kilometers (1.9 miles) wide at a resolution of 6 meters per pixel. Both are illuminated by sunlight from the upper left.

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's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

Noachis Terra. Photo: Courtesy NASA/JPL/Malin Space Science Systems