Unveiling Jupiter's polar vortices: Magnetic mysteries unraveled
Giant vortices at Jupiter's poles, which were not expected to exist, have surprised scientists. This mystery has finally been solved thanks to the analysis of archival images from the Hubble telescope.
At the poles of Jupiter, the largest planet in the Solar System, vortices that last for months are raging. They are about the size of our planet. As scientists report in the journal Nature Astronomy, these phenomena are caused by magnetic tornadoes reaching deep into Jupiter's atmosphere, lifting misty gases upwards.
Although long-lasting vortices are not uncommon on Jupiter—the most famous of them, the Great Red Spot, was observed as early as 1664 by Robert Hooke—their presence at the poles was unexpected. In the 1990s, the Hubble telescope captured dark oval shapes at both poles of the planet. In 2000, the Cassini probe confirmed the existence of this phenomenon at Jupiter's north pole.
To solve this mystery, the team led by Troy Tsubota from the University of California, Berkeley, analyzed images from the OPAL project (Outer Planets Atmosphere Legacy). Over 28 years of observations, eight dark ovals at the south pole and two at the north pole were identified. These ovals appear within a month and disappear after a few weeks.
Jupiter's mystery solved
Researchers have determined that these vortices are caused by Jupiter's strong magnetic field, which is approximately 20,000 times stronger than Earth's. Charged particles from the volcanoes on the moon Io and a ring of particles around the planet interact with the magnetic field at the poles, forming magnetic vortices. These vortices draw dense, misty gases from deep atmospheric layers, which absorb ultraviolet radiation, making these areas appear darker.
The haze in the dark ovals is 50 times thicker than the typical concentration – explained team member Xi Zhang from the University of California, Santa Cruz, as quoted by the website welt.de.
Vortices at Jupiter's poles are thus a result of volcanism on Io, caused by the planet's strong gravitational influence. These discoveries are significant for understanding Jupiter and may also aid in studying large gaseous planets orbiting other stars.
