The Never-Ending Stormy

1876—The year of the first recorded storm on Saturn, which new research published in Science Advances has found still lingers in the planet’s atmosphere almost 150 years later. By studying radio emissions from Saturn, researchers were able to follow the movement of ammonia in the planet’s atmosphere after the most recent storm in 2010–11. They found anomalous sections of the atmosphere where the concentration of ammonia was diminished at higher altitudes but was more abundant at lower altitudes, which they believe represent areas of ammonia precipitation falling—possibly as hail-like “mushballs”—from the upper atmosphere and then evaporating and remaining in the lower atmosphere as vapor. “On Earth, if you have a heavy rain, you accumulate water on the ground in puddles,” explains the study’s lead author, Cheng Li of the University of Michigan. “But on giant planets there’s no surface, so where could that rain go? It just evaporates.” The most surprising discovery was that anomalous areas were found that correspond to all six of the recorded giant storms on Saturn, including one from 1876, and they even found traces from a storm they believe is decades older than that. It is not known what causes Saturn’s megastorms, which are similar to Earth’s hurricanes but much larger, with the 2010–11 storm spanning 2,000 kilometers across. “We know that these storms are big, but based on our daily experience of weather we’ve never considered the possibility that these storms can leave such a long remnant after hundreds of years,” Li says. “On Earth, weather comes and goes, but on Saturn it sticks around.” [Source: New Scientist]