[Hubble catches a comet disintegrating into oblivion]The unlikely cloud type was first spotted decades ago by NASA's Voyager 1 spacecraft. NASA's Cassini mission recently spotted a second example of this crazy kind of cloud. When they used Cassini's instruments to puzzle out the chemical composition of the ice cloud and its surroundings, scientists came up with the same impossible answer: The stratosphere-dwelling ice cloud is made of dicyanoacetylene, but the stratosphere is sorely lacking in that particular compound. In the case of these strange ice clouds on Titan, the amount of dicyanoacetylene vapor present in the area shouldn't be enough to keep the ice trapped in the cloud in equilibrium. "The appearance of this ice cloud goes against everything we know about the way clouds form on Titan," lead study author Carrie Anderson of NASA's Goddard Space Flight Center said in a statement.

Source: Washington Post September 21, 2016 14:42 UTC