Jupiter’s Great Red Spot, described as a “persistent anticyclonic storm” considerably larger than Earth—up to 3x as big—has been raging since at least 1831, when it was first discovered. Scientists believe this storm is a permanent and stable feature of our solar system’s largest planet; it’s so large you or I could spot it using nothing but an Earth-based telescope. But, as NASA researchers recently discovered, the giant planetary mole is actually shrinking at an alarming rate, suggesting that it might not be so permanent after all.

In a series of images shared by NASA, we can see plain as day that the planet’s trademark Great Red Spot is getting smaller—now about the size of a single Earth. According to observations, Jupiter’s beauty mark is approximately 10,250 miles across; Jupiter itself is about eleven times as big as our own home planet (the sun, meanwhile, is about ten times as big as Jupiter, just to provide some context). As far back as the late 1800s, researchers estimated the storm to be about as large as 25,500 miles on its long axis, NASA noted.