Jupiter’s Great Red Spot may be the most iconic feature of any planet in our solar system, and yet scientists have come to the astonishing conclusion that it may disappear in our lifetimes. The huge megastorm may only have another 10 to 20 years left beforeo it dies, based on data collected by NASA’s Juno spacecraft.

Back in the 1800s, scientists estimated the powerful storm was so big that four Earths could fit inside it. But today it is only about 1.3 times the size of Earth, and it may be on death’s door. The Great Red Spot has been able to live so long because it is caught between two jet streams moving in opposite directions, but conditions are changing.

Its disappearance would be quite a momentous occasion in the history of our solar system, as the storm has likely been around for more than 350 years. It’s already a lot smaller than it was in the 1970s, when Voyagers 1 and 2 flew past it and measured it at about the size of two Earth widths.

“In our new observations it is apparent very small eddies are feeding into the storm,” said Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a 2014 statement. “We hypothesized these may be responsible for the accelerated change by altering the internal dynamics and energy of the Great Red Spot.”