Hubble took this sequence of amazing pictures, showing the Great Red Spot – a storm far larger than our entire planet – chewing up and spitting out a smaller, though still ginormous, storm.
In the first panel you can see the smaller storm on the left (this is the same storm we saw in May, when Jupiter suddenly got acne). In the middle panel, taken about six weeks later, it just contacts the Spot. Over the next few days it swept around and below the Spot, and got tossed out the other side, seen in the last panel. Storms on Jupiter do this all the time; sometimes the smaller ones survive and sometimes they merge into the bigger storms. I can’t imagine what this might look like from a distance of, say, 1000 km above the cloud tops. Holy cow.
During this whole encounter, the storm known as Oval BA – no relation to me – can be seen below the GRS. The Hubble pictures are pretty close to true color, so this represents more or less what you’d see if you were there. I’m surprised to see that BA has faded some in the middle. It used to be white, then turned red, and now it looks like its undergoing yet another change. Red coloring in storms is usually a sign that organic material from deep in Jupiter’s atmosphere is being dredged up, or that UV light from the Sun is affecting the molecules in the storm. A fading of BA may mean the storm has dropped in altitude, or that it’s weakening.
As you can see, Jupiter is a really dynamic planet. We’re only seeing snapshots here… but you’ve seen weather reports on Earth showing the goofy reporter standing on a sidewalk holding on for dear life while a hurricane blows, right? And yet, despite their strength and chaos, from space terrestrial hurricanes look majestic and slow, almost stationary.
But even the most monstrous Earthly storm would be a blip in this picture of Jupiter, barely visible. And the wind speeds in the GRS and BA are about 620 kph (390 mph), more than twice the speeds in Earth’s most terrible hurricanes.
Yeah, that picture may make Jupiter look stately, but it’s really a ferocious and terrifying place.
Let me add that now is a good time to see for yourself; Jupiter is rising in the east right after sunset, well placed for observing. You can see its moons with binoculars, and with a decent telescope you can see the Great Red Spot yourself (find a nearby star party if you don’t own a ‘scope). Take a look at it and remember: it may look like a fuzzy spot from here, 600 million km away, but its larger than worlds. Including ours.