Jupiter, known for its famous Great Red Spot, holds another atmospheric mystery: massive dark ovals at the poles, the size of Earth.
They appear and disappear, visible only in ultraviolet light, and scientists attribute their appearance to tornado-like phenomena.
Dark ovals often appear in Jupiter’s south polar regions, but not all the time, forming in about a month and dissipating in a few weeks. Only 75 percent of annual observations of the giant planet by NASA’s Hubble Space Telescope between 1994 and 2022 detected them, they note Noi.md with reference to .
The dark oval shapes are much less common near Jupiter’s north pole, where they appear in only a few of the 25 annual images. Ovals are dark in ultraviolet light because they absorb more light than the surrounding atmosphere.
Jupiter’s atmosphere contains rapidly rotating vortices. They are caused by strong magnetic field lines that interact both with charged particles high above the atmosphere and with the plasma emanating from Io, one of Jupiter’s satellites and the most active volcanic site in the Solar System.
The eddies propagate from the upper atmosphere and weaken as they move deeper, but the turbulence they cause excites the stratosphere, forming patches of dense fog.
