Jupiter's polar vortices unravelled: Mystery of magnetic storms
Giant vortices at Jupiter's poles, which were previously thought not to exist, have surprised scientists. Thanks to the analysis of archival images from the Hubble Telescope, the mystery has finally been unravelled.
At the poles of the largest planet in the Solar System, vortices that persist for months are raging, each as large as our planet. As reported by scientists in the journal "Nature Astronomy", these phenomena are caused by magnetic tornadoes that penetrate deep into Jupiter's atmosphere, lifting misty gases upwards.
Although long-lasting vortices are not unusual on Jupiter – the most famous being the Great Red Spot, first observed in 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 presence of this phenomenon at Jupiter's north pole.
To solve this puzzle, the team led by Troy Tsubota from the University of California, Berkeley, analysed images from the OPAL project (Outer Planets Atmosphere Legacy). Over 28 years of observation, eight dark ovals at the South Pole and two at the North Pole were identified, appearing within a month and disappearing after a few weeks.
Jupiter's mystery solved
Researchers have determined that these vortices are caused by Jupiter's powerful magnetic field, which is 20,000 times stronger than Earth's. Charged particles from the volcanoes on the moon Io, along with 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 within the atmospheric layers, absorbing ultraviolet radiation, which makes these regions 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, influenced by the planet's strong gravitational pull. These discoveries are significant for understanding Jupiter and may assist in studying large gaseous planets orbiting other stars.
