Hazed And Confused: Magnetic Tornadoes Are Wreaking Havoc On Jupiter

Jupiter is well-known for its Great Red Spot, but astronomers have recently discovered equally large spots at the giant gas planet’s north and south poles that appear and disappear at random. The dark UV ovals were first spotted by NASA’s Hubble spacecraft in the late 1990s, but have only recently been studied in depth.

The mysterious spots on Jupiter have been the focus of a new study by a group of astronomers at the University of California, Berkeley. The spots, visible only in ultraviolet light, are embedded in stratospheric haze layers located at the gas giant’s north and south poles. According to the study, the dark ovals absorb more UV light than their surroundings, causing them to appear dark in images captured by NASA’s Hubble Space Telescope.

The astronomers remarked, “Using 26 global maps of Jupiter taken by Hubble between 1994 and 2022, we detected transient ultraviolet-dark ovals with a 48% to 53% frequency of occurrence in the south. We found the southern dark oval to be 4 to 6 times more common than its northern counterpart.”

In a press release from the University of California, Berkeley, the group of astronomers indicated that the dark UV ovals hint at unusual processes taking place in Jupiter’s strong magnetic field that spread down to the poles and into the planet’s atmosphere, even deeper than the magnetic processes that produce the phenomenal auroras on Earth.

Two experts on planetary atmospheres were consulted during the study, Tom Stallard at Northumbria University and Xi Zhang at UC Santa Cruz, to help determine what could cause the areas of dense haze. Stallard theorized the dark oval is likely “stirred from above by a vortex created when the planet’s magnetic field lines experience friction in two very distinct locations.” Those locations being in the ionosphere, and in the sheet of hot, ionized plasma around the planet shed by Jupiter’s moon Io.

Zhang added, “The haze in the dark ovals is 50 times thicker than the typical concentration, which suggests it likely forms due to swirling vortex dynamics rather than chemical reactions triggered by high-energy particles from the upper atmosphere.” He also remarked that the group’s observations showed the timing and location of these energetic particles do not correlate with the appearance of the dark ovals.

The group theorizes the vortex spins fastest in the ionosphere, and progressively weakens as it reaches each deeper layer. Much like a tornado touching down on a dusty patch of Earth, the deepest extent of the vortex may be stirring up the hazy atmosphere to create the dense spots. However, the group points out it is still not clear if the mixing produces more haze from below or generates additional haze.

Zhang points out that studying connections between different atmospheric layers is important for all planets, whether an exoplanet, Jupiter, or Earth. By studying aspects such as possible magnetic tornados causing dark spots at Jupiter’s poles, it helps astronomers and scientists better understand Jupiter as a whole.