Space Telescope Science
Three billion miles away on the farthest known major planet in our solar system, an ominous, stinky, dark storm is shrinking out of existence as seen in pictures of Neptune taken by the Hubble Space Telescope. Immense dark storms on Neptune were first discovered in the late 1980s by the Voyager 2 spacecraft. Since then, only Hubble has tracked these elusive features that play a game of peek-a-boo over the years. Hubble found two dark storms that appeared in the mid-1990s and then vanished. This latest storm was first seen in 2015, but is now shrinking away. The dark spot material may be hydrogen sulfide, with the pungent smell of rotten eggs.