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
Opportunity (rover) early June 2018, a large global-scale dust storm developed and within a few days the rover's solar panels were not generating enough power to maintain communications, with last contact on June 10, 2018. NASA stated they did not expect to resume communication until after the global dust storm subsided, but the rover kept silent even after the storm ended in early-October, suggesting either a catastrophic failure or a layer of dust covered its solar panels. The team remains hopeful that a windy period between November 2018 and January 2019 may clear the dust from its solar panels, as has happened