Earth’s atmosphere is in such constant flux that we have a tired old saying about it: “If you don’t like the weather, wait five minutes.” If we lived on Jupiter — where a single storm has been raging uninterrupted for almost two centuries, and possibly much longer — we’d have to muster more patience.
But perhaps we wouldn’t have to wait forever. The Great Red Spot, an enormous high-pressure system which astronomers have tracked regularly since the late 19th century, is steadily dwindling. In its heyday, at 25,500 miles across, it was large enough to engulf our planet three times over; now it hardly spans a single Earth.
As of January, based on the latest data from the Hubble Space Telescope, the spot measures just 8,700 miles across and 5,800 miles high (that is, latitudinally). That’s in line with a consistent, decades-old trend. And while it's unclear whether our solar system’s most famous planetary feature will ever vanish entirely, there’s no reason to think its decline will stop or reverse anytime soon.
“It is still shrinking,” says Amy Simon, a senior scientist at the NASA Goddard Space Flight Center. Like last year and the year before, “It's the smallest size we've ever measured it at. That’s definitely not changing.”
