A colossal shield volcano on Mars…

A colossal shield volcano on Mars, among the tallest in the solar system. It stands roughly twenty-two kilometres high, nearly two and a half times the height of Everest, and its base covers roughly the area of Poland. Steep cliffs several kilometres high ring its edge. Named after the home of the Greek gods, it was first imaged in detail by the Mariner 9 orbiter, which reached Mars in 1971.

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