Pioneer Venus 1 was the first spacecraft to map the surface of Venus (right).
Though it found Venus to be generally smoother than Earth, it found a mountain 2 km (about one mile) higher than Mt. Everest and a canyon about 1.1 km (about 2/3 of a mile) deeper than the Grand Canyon.
The International Astronomical Union named almost all of the features discovered by Pioneer Venus 1 and subsequent missions after historical or mythological women.
