Transit of Mercury last four transits occurred on November 15, 1999; May 7, 2003; November 8, 2006; and May 9, 2016. The next will occur on November 11, 2019, and then on November 13, 2032. A typical transit lasts several hours. On June 3, 2014, the Mars rover "Curiosity" observed the planet Mercury transiting the Sun, marking the first time a planetary transit has been observed from a celestial body besides Earth. More generally, transits can also occur for Venus and were investigated in the context of searching for the hypothetical inner planet Vulcan. The most common observation to be made at a
Curiosity (rover) California, where she signed her name directly onto the rover as it was being assembled. Ma wrote in her winning essay: "Curiosity" landed in Quad 51 (nicknamed Yellowknife) of Aeolis Palus in Gale Crater. The landing site coordinates are: . The location has been named Bradbury Landing in honor of science fiction author Ray Bradbury. Gale crater, an estimated 3.5 to 3.8 billion-year-old impact crater, is hypothesized to have first been gradually filled in by sediments; first water-deposited, and then wind-deposited, possibly until it was completely covered. Wind erosion then scoured out the sediments, leaving an isolated mountain, Aeolis Mons