November 13, 2021
Today in 1971, Mariner-9, the first man-made object to orbit another planet, entered Martian orbit. The mission of the unmanned craft was to return photographs mapping 70% of the surface, and to study the planet’s thin atmosphere, clouds, and hazes, together with its surface chemistry and seasonal changes.
Orbital view of Olympus Mons taken by Mariner 9 in January 1972. Olympus Mons a giant shield volcano measuring over 21.9 kilometers tall – more than twice as tall as Mt. Everest at sea level. Credit: NASA/National Gallery of Victoria, Melbourne