Jupiter’s Great Red Spot might not be losing its greatness after all. Although the storm has been dwindling for about a century and a half, a new study published in the Astronomical Journal shows that while its length continues to decrease, its height is actually increasing. The new discovery adds to the storm’s list of unpredictable behaviors.

“Storms are dynamic, and that’s what we see with the Great Red Spot. It’s constantly changing in size and shape, and its winds shift, as well,” said Amy Simon, planetary atmosphere expert at NASA’s Goddard Space Flight Center and lead author of the paper, in a press release.

Observations of the Great Red Spot have been quite extensive over the years, giving researchers a solid record to look back on. The first confirmed observation dates back to 1831, and although technology wasn’t too advanced at the time, observers were able to track the storm’s size and drift by placing eyepieces marked with crosshairs on their telescopes.

By using this technique, and other methods as technology advanced, observations have been logged at least once a year since 1878. More recent data has been collected by the two Voyager missions, starting in 1979, and yearly observations by the Outer Planets Atmospheres Legacy program, which uses NASA’s Hubble Space Telescope and is run by scientists from NASA’s Jet Propulsion Laboratory and the University of California at Berkeley.

Simon and her team of researchers combined these records to study changes in the storm’s size, color, shape, drift rate, and wind speed, and found that the Great Red Spot is now only about a third the size of its 1878 width . At one point, the storm was large enough to house three Earths, but now it’s barely large enough to harbor one.