New images taken by the Hubble Space Telescope of gas giant planets Jupiter and Uranus have been published that show intriguing interplanetary weather conditions.
Taken by Hubble’s Wide Field Camera 3 as part of the annual Outer Planet Atmospheres Legacy (OPAL) program, the new images of Jupiter taken in November 2022 and January 2023 show the planet’s famous “Great Red Spot,” an anticyclonic storm roughly the diameter of Earth. However, they also show a wave of cyclones and anticyclones moving clockwise and counterclockwise, all of which have appeared in the last 10 years.
In the image above (this article’s main image) it’s possible to see Jupiter’s orangey moon Io—the most volcanic body in the entire solar system—as it transits the giant planet to cast a dark shadow up its colorful cloud tops. It’s visible below, too, in the left-hand image.
[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 apparen
NASA, ESA, STScI, A. Simon (NASA
On the right of this image (above) you can see the Great Red Spot. A 400-years old storm that used to be twice the size of Earth, but has since shrunk slightly, it’s rolling counterclockwise between two bands of clouds that are moving in opposite directions toward it. Inside winds blow at 425 miles per hour.
On the right-hand image you can see Jupiter’s icy moon Ganymede transiting the giant planet. It’s the largest moon in the solar system—even bigger than planet Mercury and dwarf planet Pluto—and is the only moon known to have a magnetic field.
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. [Image description: Jupiter looms large in this image. Set against a black background, the planet is banded in stripes of brownish orange, light gray, soft yellow, and shades of cream. White and cream colored ovals punctuate the planet at all latitudes. The icy moon Ganymede appears as a gray, mottled orb crossing the face of Jupiter.]
NASA, ESA, STScI, A. Simon (NASA
Next month Europe’s JUICE spacecraft (Jupiter Icy Moons Explorer) will launch to eventually orbit Ganymede, though the journey will take eight years.
Close to the Great Red Spot is the Great Red Worm—to the top-right of the massive storm in this image— a reddish sausage-shaped vortex spinning in the opposite direction. The white white ovals beneath and behind Ganymede are anticyclones—smaller versions of the Great Red Spot.
Planetary oddball Uranus rolls around the Sun on its side as it follows its 84-year orbit, rather … [+] than spinning in a more ’vertical’ position as Earth does. Its weirdly tilted ‘horizontal’ rotation axis is angled just eight degrees off the plane of the planet’s orbit. One recent theory proposes that Uranus once had a massive moon that gravitationally destabilised it and then crashed into it. Other possibilities include giant impacts during the formation of the planets, or even giant planets exerting resonant torques on each other over time. The consequences of Uranus’s tilt are that for stretches of time lasting up to 42 years, parts of one hemisphere are completely without sunlight. When the Voyager 2 spacecraft visited during the 1980s, the planet’s south pole was pointed almost directly at the Sun. Hubble’s latest view shows the northern pole now tipping toward the Sun. [LEFT] – This is a Hubble view of Uranus taken in 2014, seven years after the northern spring equinox when the Sun was shining directly over the planet’s equator, and shows one of the first images from the OPAL programme. Multiple storms with methane ice-crystal clouds appear at mid-northern latitudes above the planet’s cyan-tinted lower atmosphere. Hubble photographed the ring system edge-on in 2007, but the rings are seen starting to open up seven years later in this view. At this time, the planet had multiple small storms and even some faint cloud bands. [RIGHT] – As seen in 2022, Uranus’s north pole shows a thickened photochemical haze that looks similar to the smog over cities. Several little storms can be seen near the edge of the polar haze boundary. Hubble has been tracking the size and brightness of the north polar cap and it continues to get brighter year after year. Astronomers are disentangling multiple effects — from atmospheric circulation, particle properties, and chemical processes — that control how the atmospheric polar cap changes with the seasons. At t
NASA, ESA, STScI, A. Simon (NASA
Meanwhile, Uranus—also captured by Hubble—displays a growing polar cap of high-altitude haze. It looks rather like smog over a city. You can see it growing in these two photos, above, from November 2014 and November 2022, respectively.
As seen in 2022, Uranus’s north pole shows a thickened photochemical haze that looks similar to the … [+] smog over cities. Several little storms can be seen near the edge of the polar haze boundary. Hubble has been tracking the size and brightness of the north polar cap and it continues to get brighter year after year. Astronomers are disentangling multiple effects — from atmospheric circulation, particle properties, and chemical processes — that control how the atmospheric polar cap changes with the seasons. At the Uranian equinox in 2007, neither pole was particularly bright. As the northern summer solstice approaches in 2028 the cap may grow brighter still, and will be aimed directly toward Earth, allowing good views of the rings and the north pole; the ring system will then appear face-on. This image was taken on 10 November 2022. [Image description: Uranus appears tipped on its side. Set against a black background, the planet is mainly colored cyan. It looks like a flat circle outlined with a pinkish gray limb. A faint, pink ring encircles the planet nearly vertically. The faint ring appears to be almost face on. A large area of white coves much of the right side of the planet.]
NASA, ESA, STScI, A. Simon (NASA
Uranus takes 84 years to orbit the Sun, but rotates on its side, so for up to half a year (equal to 42 Earth-years) large parts of one hemisphere are completely hidden from sunlight. These images from Hubble show Uranus’ north pole tipping towards the Sun, while NASA’s Voyager 2 probe—which conducted a flyby in the 1980s—imaged its south pole.
As well as Jupiter and Uranus, the annual OPAL project studies the atmospheric dynamics and evolution of Saturn and Neptune. It uses Hubble’s 16 megapixel Wide Field Camera 3 (WFC3) to create the 360° mosaics of planets you see here.
