The Storm That Stayed

That reads like a joke setup. It's a weather report. Astronomers tracked three white oval storms in Jupiter's southern hemisphere continuously from 1939 — sixty years of well-behaved white blobs, each older than most of the people watching. Then, between 1998 and 2000, they combined: two merged, and the survivor swallowed the third. It got a name only an institution could produce. Oval BA.

Then, late in 2005, it began turning red.

Nobody told it to. There is no committee on Jupiter. There is also no ground on Jupiter — no coastline for a hurricane to grind itself out against, no friction, nothing but roughly 1,300 Earth-volumes of hydrogen and helium spinning very fast in the dark. Weather there doesn't end. It just changes management.

Amateur astronomers caught the color shift first: people in backyards noticed a planet redecorating. By April 2006, Hubble's Advanced Camera for Surveys had it pinned three times in a month — the sharpest look anyone had ever gotten at a red spot in the act of becoming one.

They called it Red Spot Jr.

Be precise about what changed, though, because it wasn't the storm. The storm had been there for decades. What changed was pigment — a ring around the vortex core going from white to red in about five months. Modeling published just this month puts that color in a haze of chromophore particles near the 0.2-bar level, and finds the likeliest driver isn't new material arriving. It's a change in how much of it you can see: gas subsiding within the ring, the same stuff getting denser to look at.

Philip Marcus, a fluid dynamicist at UC Berkeley, had called it in advance — arguing in 2004 that losing the white ovals would leave Jupiter mid-reorganization, redistributing heat between equator and pole, shifting average temperatures at some latitudes by as much as 10 degrees Fahrenheit. On that reading the red ring isn't a novelty. It's a symptom.

So nothing was created. Something crossed a threshold — which is a better story than a birth, because a birth implies a clean line, before and after. This was a phase transition: same matter, different state, no new ingredient.

Then, in July, the two red spots passed each other.

On the night of July 20, 2006, Hawaii time, the Keck II telescope caught Red Spot Jr. sliding by the Great Red Spot — whose winds run up to 400 miles per hour, and which has been watched longer than any storm known to us. Junior got squashed, stretched along its direction of travel by the fluid rudeness of the bigger storm.

And then it kept going. Didn't merge, didn't dissipate. Resumed its own eastward lap around a planet that has no idea any of this is occurring.

Twenty years is long enough to find out what that was worth.

The red didn't hold. In 2018, over a few months, Oval BA's annulus went white again — back to nearly the color it was when it formed. Then it reddened once more. The pigment, it turns out, is not a state the storm achieved in 2006. It's something the storm does, and undoes, and does again, on a timescale of about half a year, while the vortex underneath persists through all of it.

And the Great Red Spot — the furniture, the thing on every poster, the one we point to in textbooks and say that's just how it is — is going away. In the late 1800s it spanned about 41,000 kilometers, wide enough to line up three Earths inside it. Voyager measured 23,335 in 1979. By 2014 it was under 16,500 and still narrowing, roughly a thousand kilometers a year, an oval rounding into a circle, wobbling on a ninety-day cycle nobody can explain.

It's also younger than we said. A 2024 analysis of the historical record concluded that the dark oval Cassini named the Permanent Spot in 1665 was lost by 1713 and is not the storm we watch now — that today's Great Red Spot was first clearly seen in 1831, making the most permanent-looking object in the solar system younger than the modern newspaper.

So the account runs backwards. Not: the universe occasionally makes a new permanent thing. Rather: nothing there is permanent, and permanence was only ever a word for slow. Three ovals fold into one. The one blushes, pales, blushes again. The ancient thing shrinks. Cassini's spot vanished outright and we spent three centuries assuming it hadn't. Emergence and dissolution aren't two events. They're one process, and which one you're looking at depends entirely on when you happened to glance.

Nothing is broken. Jupiter isn't malfunctioning — it's becoming, continuously, with no committee and no destination. Stability there isn't a state you achieve and defend. It's something that has to keep happening, and can stop.

That's not a sadder ending. It's the accurate one, and the only one that includes you — because you aren't a thing that is either. You're a thing that keeps happening: order condensing out of local rules and a great deal of spinning, holding its shape for now.

Sleep well.