Jupiter (November 2022 and January 2023)

[LEFT] - The forecast for Jupiter is for stormy weather at low northern latitudes. A prominent string of alternating storms is visible, forming a ‘vortex street’ as some planetary astronomers call it. This is a wave pattern of nested cyclones and anticyclones, locked together like the alternating gears of a machine moving clockwise and counterclockwise. If the storms get close enough to each other and merge together, they could build an even larger storm, potentially rivalling the current size of the Great Red Spot. The staggered pattern of cyclones and anticyclones prevents individual storms from merging. Activity is also seen interior to these storms; in the 1990s Hubble didn’t see any cyclones or anticyclones with built-in thunderstorms, but these storms have sprung up in the last decade. Strong colour differences indicate that Hubble is seeing different cloud heights and depths as well.

The orange moon Io photobombs this view of Jupiter’s multicoloured cloud tops, casting a shadow toward the planet’s western limb. Hubble’s resolution is so sharp that it can see Io’s mottled-orange appearance, the result of its numerous active volcanoes. These volcanoes were first discovered when the Voyager 1 spacecraft flew by in 1979. The moon’s molten interior is overlaid by a thin crust through which the volcanoes eject material. Sulphur takes on various hues at different temperatures, which is why Io’s surface is so colourful. This image was taken on 12 November 2022.

[RIGHT] - Jupiter’s legendary Great Red Spot takes centre stage in this view. Though this vortex is big enough to swallow Earth, it has actually shrunk to the smallest size it has ever been according to observation records dating back 150 years. Jupiter’s icy moon Ganymede can be seen transiting the giant planet at lower right. Slightly larger than the planet Mercury, Ganymede is the largest moon in the Solar System. It is a cratered world and has a mainly water-ice surface with apparent glacial flows driven by internal heat. This image was taken on 6 January 2023.

This image is smaller in size because Jupiter was 130,000 kilometres farther from Earth when the image was taken.

[Image description: Two views of the giant gas planet Jupiter appear side-by-side for comparison.]