Although more eroded and not as tall, the newly discovered volcano rivals the others in diameter. It’s about 450 km across. The volcano sits on the eastern edge of a broad rise called Tharsis, home to 3 other well-known giant volcanoes.
For a quiet, dusty lump of a planet we see today, Mars has had a surprisingly violent history, one that could reveal some clues about Earth.
When researchers reconstructed lava flows on Mars, they realized the red planet is a lot more active than they previously thought.
Most meteorites from Mars are just a few hundred million years old, and likely come from relatively recent volcanic events such as the eruptions on the largest volcano in the solar system, Olympus Mons.
