Scientists are witnessing an absolutely stunning event with the Hubble Space Telescope, as a huge storm on the surface of Neptune disappears before their very eyes. The storm was first observed by NASA’s Voyager 2 spacecraft when it flew by Neptune in 1989, where it saw large, dark storms throughout the atmosphere of the ice giant.

Scientists have been monitoring Neptune with Hubble, and have witnessed new storms materialize. But it appears these storms only last a few years, and now researchers are able to watch one start to vanish before their eyes for the first time ever. Even more interestingly, it is behaving in a way that scientists did not expect.

Experts had put such storms through simulations which indicated that the vortex of the storm would slowly drift to the equator, where it would break up and perhaps cause a stunning display. But scientists are witnessing this storm move toward the south pole, where it is slowly disappearing.

“We have no evidence of how these vortices are formed or how fast they rotate,” said Agustín Sánchez-Lavega from the University of the Basque Country in Spain, in a statement. “It is most likely that they arise from an instability in the sheared eastward and westward winds.”

“It looks like we’re capturing the demise of this dark vortex, and it’s different from what well-known studies led us to expect,” added Michael H. Wong of the University of California at Berkeley. “Their dynamical simulations said that anticyclones under Neptune’s wind shear would probably drift toward the equator. We thought that once the vortex got too close to the equator, it would break up and perhaps create a spectacular outburst of cloud activity.”