Jupiter's South Pole

The South Pole of Jupiter was first photographed in detail by the Juno spacecraft, which arrived at Jupiter in July 2016 and entered a polar orbit. In the images it returned, six cyclones were discovered at the planet's South Pole. Five of the polar cyclones encircle a center vortex. Additionally, in 2007 and 2016, data collected by X-ray telescopes orbiting Earth suggested Jupiter's South Pole has an aurora. This is attributed to Jupiter having a strong magnetic field, which causes the aurora to form an ovular shape, known as the Southern Auroral Oval. Using UV instruments, researchers have been able to observe reflected sunlight, from which they have identified an increase in acetylene (C2H2) absorptions in Jupiter's Southern Auroral Oval.

History of exploration

The earliest missions to observe Jupiter closely were Pioneer 10 and Pioneer 11. In 1973, Pioneer 10, at its closest, passed Jupiter at a distance of 81,000 miles, which captured images and collected infrared readings of the planet's atmosphere. In 1974, Pioneer 11 flew within 26,400 miles from the planets surface, solely capturing images of the planets surface. Later missions, being that of Voyager 1 and Voyager 2, prioritized observation of Jupiter's ring and its moons. After the implementation of orbital planetary exploration, the only probe that had orbited Jupiter, besides Juno, was Galileo, from 1995 to 2003; however, its orbital inclination made it impossible to observe the polar regions of Jupiter; Cassini, a non-orbital spacecraft, flew past Jupiter in 2000, and had no opportunity to photograph the polar regions. Thus, they remained largely unknown until the observations during the Juno mission in 2016 (the images of the previous flyby missions and Earth telescopes had low resolution); however, in 2000, the polar X-ray spots of Jupiter (the southern one is significantly weaker than the northern one) were detected.