Mysterious X-rays from Jupiter’s Northern Lights suggests that the giant planet’s “northern lights” may have unexpected similarities with Earth’s, a new study finds.
Auroras, the shining rays, known as northern or southern lights on Earth, seen over 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 slam into a planet’s magnetosphere – the region controlled by a world’s magnetic field – and flow down its magnetic field lines to collide with molecules in its atmosphere.
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Jupiter’s auroras also emit unusual X-rays, those emitted by electrically charged sulfur and oxygen ions emitted by Jupiter’s volcanic moon Io. Jupiter’s X-ray neuroror alone releases each about a gigawatt, about what a power plant on Earth can produce for several days. These X-ray neurors often pulsate like clockwork, in regular strokes a few dozen minutes long for dozens of hours.
The specific mechanisms that drive these flares have long been a mystery. “For more than 40 years, we have been wondering what could be causing Jupiter’s spectacular X-ray neurora,” co-author Zhonghua Yao, a planetary scientist at the Key Laboratory of Earth and Planetary Physics in Beijing, tells Space.com.
To uncover the sources of these flares, scientists used NASAs Juno probe orbiting Jupiter to inspect the giant planet’s magnetosphere close to July 16 and July 17, 2017. At the same time, they had the European Space Agency’s XMM-Newton telescope orbiting the Earth, remote analysis of X-rays Jupiter.
The researchers discovered that the X-rays are apparently triggered by regular vibrations of Jupiter’s magnetic field lines. These vibrations generate plasma waves of plasma – clouds of electrically charged particles – that send heavy ions “surfing” along the magnetic field lines until they smash into the planet’s atmosphere and release energy in the form of X-rays.
Similar plasma waves help generate northern lights on Earth. Despite the fact that Jupiter is so much larger than Earth in every way – such as larger mass and diameter, more energy, stronger magnetic fields and faster rotation – it seems that the processes responsible for Jupiter’s ionurora and Earth’s ionurora are the same, “co-lead author William Dunn, an astrophysicist at University College London, tells Space.com.” This suggests a potentially universal process for space environments. “
It remains unclear why Jupiter’s magnetic field lines vibrate regularly. The possibilities include interactions with the solar wind or with high-velocity plasma currents within Jupiter’s magnetosphere, the researchers said.
The electrically charged particles that scientists discovered that meandered toward Jupiter’s poles may not appear to have enough energy to generate X-ray neuras, “so they have to undergo a little extra acceleration along the way,” Yao said. “What are these extra acceleration processes?”
The scientists suggested that enormous voltages that may exist across Jupiter’s atmosphere could accelerate these electrically charged particles “toward the atmosphere with colossal energies,” Dunn said. “These probably play a key role.”
In the future, Yao suggested exploring other worlds to see if plasma waves might also help propel the Northern Lights there. Similar activity can occur around Saturn, Uranus, Neptune and probably also exoplanets, where different kinds of charged particles “surf” the waves, he said.
The researchers detailed their findings online today (July 9) in the journal Science Advances.
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