Today in the history of astronomy, the first spacecraft to orbit another planet begins orbiting Mars.
When Mariner 9 reached Mars, it found the world overshadowed by a giant dust storm. Once the storm cleared, the spacecraft began the process of mapping the Red Planet. Credit: NASA/JPL
- Mariner 9, launched on May 30, 1971, entered Mars orbit on November 13, 1971, becoming the first spacecraft to orbit another planet.
- Following the failure of its counterpart Mariner 8, Mariner 9 inherited an expanded mission profile, which included surface mapping, atmospheric monitoring and analysis, surface data collection, and the acquisition of approximately 3,000 photographs.
- Upon reaching Mars, Mariner 9 encountered a global dust storm; However, its design for longevity enabled it to continue and resume its mission even after the storm subsided.
- Over nearly a year, Mariner 9 returned 7,329 photographs, mapping 85% of the Martian surface, and revealing a dynamic world featuring shield volcanoes, dry river valleys, and polar ice, in addition to providing close-up views of Phobos and Deimos.
On May 30, 1971, Mariner 9 departed on its mission to Mars. On November 13, 167 days later, it entered the orbit of Mars, making it the first spacecraft to orbit another planet.
Along with Mariner 8, Mariner 9 was half of the Mars 71 mission. But when Mariner 8 launched on May 9, it failed to reach orbit and fell from the sky after five minutes and crashed into the Atlantic Ocean. As a result, Mariner 9 inherited all of Mariner 8’s goals in addition to its own, giving it an expanded list of objectives: surface mapping, atmospheric monitoring and analysis, surface data collection, and returning approximately 3,000 photographs.
When Mariner 9 reached Mars, it encountered a global dust storm. Because it was designed for longevity, the orbiter was able to wait out the storm and then resume its mission. (The Soviet spacecraft Mars 2 and Mars 3 did not fare as well.) Over the course of about a year, Mariner 9 returned 7,329 photographs and mapped 85% of the Martian surface. It also revealed a dynamic and active world – including shield volcanoes, dry river valleys, ice at the poles of Mars – and gave researchers close-up views of the surfaces of Phobos and Deimos.
