Color of Jupiter’s Great Red Spot Comes from Epic Sunburn

The Great Red Spot on Jupiter’s face is secretly dull in color. But the swirling storm looks crimson thanks to something like a cosmic “sunburn,” scientists say.

New experiments show that the gases in the upper atmosphere of Jupiter turn a reddish hue when they’re hit with sunlight. Underneath, the Great Red Spot probably looks gray or white.

“Spot” might be a bit of a misnomer for the most powerful storm in the solar system. The vortex is wider than two Earths, at about 7,500 miles (12,000 km) across, and it packs winds up to 425 mph (680 km/h). The storm is also extremely long-lived; it has been present on Jupiter ever since astronomers started observing the planet through telescopes, making it centuries old at least.

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It is caused by focus of sunlight rather than total sunlight?

Do all planets have a focus of sunlight? as well as total sunlight

> New experiments show that the gases in the upper atmosphere of Jupiter turn a reddish hue when they’re hit with sunlight. Underneath, the Great Red Spot probably looks gray or white.

Oh yuk. Very unlikely.

The top of Jupiter’s atmosphere is clear, then as you go down it changes in turn to white, brown, red and finally black. The last black layer was seen when SL-9 hit. The stronger the vertical component of atmospheric convection, the deeper the layer that gets dredged up into view. That sequence of clear-white-brown-red-black is actually one of density, if you could stop the convection then all the colours of the deeper layers would sink back into the deeper atmosphere leaving Jupiter looking as white as Venus.