Last week NASA released the first maps ever Venus, and Stealth Mountain was the star of the show. John Wood of the Smithsonian Astrophysical Observatory thought the Stealth material might be fresh lava. Whereas other peaks on Venus reflected radar-thanks to weathering and erosion that turned dull soil into bright, electrically conducting iron sulfide-plains surrounding the five-mile high peak called Maat Mons still wore their original, dull coat. Wood surmised it was dark lava. Even more tantalizing, the lava seemed fresh: since the harsh atmosphere on Venus chemically transforms rocks and soil, lava older than 10 or so years would have brightened up by now. This was the first evidence that Venus harbors active volcanoes. Earth’s nearest neighbor thus joined a most exclusive club: Earth, the Jovian moon Io and Neptune’s moon Triton the only other orbs known to have active volcanoes.
How often might Maat Mons and other erupting peaks repave Venus in lava? Magellan, which reached Venus 15 months after its launch in May 1989, begins its third full survey of the planet in January. The first round produced images of 80 percent of Venus’s surface; last week’s announcement marked the completion of a global map. For its third survey, Magellan will pierce the planet’s thick, corrosive clouds of sulfur dioxide with more radar to detect changes on the surface, including new lava flows, landslides and erosion. Magellan is performing flawlessly (unlike many recent NASA endeavors) and it isn’t finished yet.
