The dark UV ovals were first detected by NASA’s Hubble Space Telescope during the late 1990s at the north and south poles. During the Cassini spacecraft’s flyby of Jupiter in 2000, it also confirmed these ovals at Jupiter’s north pole, but the ovals did not get a lot of attention from scientists.

While Jupiter’s Great Red Spot has been a constant feature of the planet for centuries, University of California, Berkeley, astronomers have discovered equally large spots at the planet’s

Magnetic vortices twisting down from Jupiter's ionosphere into its deep atmosphere cause giant, ultraviolet-absorbing polar anticyclones, each the size of our Earth.

Astronomers have discovered mysterious, Earth-sized dark spots at Jupiter’s poles that appear and disappear unpredictably. These spots, only visible in ultraviolet (UV) light, are embedded in a thick haze at the poles and seem to be linked to the planet’s strong magnetic field.

The dark UV ovals were first spotted by NASA’s Hubble spacecraft in the late 1990s, but have only recently been studied in depth.

New research reveals that Jupiter’s magnetic tornadoes generate massive Earth-sized storms, visible only in ultraviolet light.