Mystery of Jupiter’s mighty X aurora finally solved
Mysterious bursts of x-rays from The Aurora of Jupiter suggest that the giant planet’s “northern lights” may have unexpected similarities to those on Earth, according to a new study.
Auroras, the shimmering displays of radiance known as northern or southern lights on Earth, are seen above the poles of a number of planets across the solar system. These dancing lights are produced when energetic particles from the sun or other celestial bodies strike a planet’s magnetosphere – the area controlled by a world’s magnetic field – and descend its magnetic field lines to collide with them. molecules of its atmosphere.
Jupiter’s magnetic field is extremely strong – about 20,000 times stronger than that of Earth – and therefore its magnetosphere is extremely large. If this alien magnetosphere were visible in the night sky, it would cover an area several times the size of our moon. As such, Jupiter’s auroras are much more powerful than those on Earth, releasing hundreds of gigawatts – enough to briefly power all of human civilization.
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Jupiter’s aurorae also emit unusual x-ray flares, those that originate from electrically charged sulfur and oxygen ions spewed out by Jupiter’s volcanic moon Io. Jupiter’s auroras X alone each release about a gigawatt, which is what a power plant on Earth could produce over several days. These X-ray auroras often pulsate like a clock, in regular beats of a few tens of minutes for tens of hours.
The specific mechanisms behind these flares have long been a mystery. “For more than 40 years, we have wondered what can cause Jupiter’s spectacular Aurora X,” study co-lead author Zhonghua Yao, a planetologist at the Key Laboratory of Earth and Planetary Physics, told Space.com. in Beijing. .
To uncover the sources of these rashes, the researchers used the Juno probe, which orbits around Jupiter, to closely inspect the magnetosphere of the giant planet on July 16 and 17, 2017. At the same time, they have remotely analyzed the X-rays of the European Space Agency XMM-Newton, which orbits around Earth. Jupiter.
Scientists have found that X-ray flares are apparently triggered by regular vibrations of Jupiter’s magnetic field lines. These vibrations generate planetary-scale plasma waves – clouds of electrically charged particles – which send heavy ions to “surf” along magnetic field lines until they shatter in the atmosphere. planet, releasing energy in the form of X-rays.
Similar plasma waves help generate auroras on Earth. As such, although Jupiter is so much larger than Earth in all respects – such as greater mass and diameter, more energy, stronger magnetic fields, and faster rotation – “it seems that the processes responsible for Jupiter’s ionic aurora and Earth’s ionic aurora are the same, ”study co-lead author William Dunn, an astrophysicist at University College London, told Space.com. “It hints at a potential universal process for space environments.”
It is still not clear why Jupiter’s magnetic field lines regularly vibrate. The possibilities include interactions with the solar wind or with high-speed plasma fluxes in Jupiter’s magnetosphere, the researchers said.
The electrically charged particles the researchers spotted rushing towards Jupiter’s poles may not appear to have enough energy to generate auroras X, “so they must undergo additional acceleration along the way,” Yao said. “What are these additional acceleration processes? “
Scientists have suggested that huge voltages that may exist above Jupiter’s atmosphere could accelerate these electrically charged particles “toward the atmosphere with colossal energies,” Dunn said. “These probably play a key role. “
Going forward, Yao suggested studying other worlds to see if plasma waves could also help drive auroras there. Similar activity can occur around Saturn, Uranus, Neptune and possibly exoplanets as well, with different types of charged particles “surfing” the waves, he said.
Scientists have detailed their discoveries online today (July 9) in the journal Science Advances.
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