Venus's volcano, named Maat Mons, looms above the volatile surface of the Earth's "unruly" twin. This image was captured by the Magellan spacecraft which also mapped 84 percent of the planet's surface in just one day—one Venus day that is, equal to 243 days on Earth. The orange tint approximates the color the human eye would see as a result of sunlight filtering through Venus's cloud cover.

(Text adapted from and photograph shot on assignment for, but not published in, "Venus Revealed," February 1993, National Geographic magazine)