Scientists have solved a decades-old puzzle about how Jupiter creates X-ray auroras that are as regular as clockwork.
The X-rays are produced by charged ion particles interacting with the planet’s atmosphere, which cause bursts of visible and invisible light.
On Earth, a similar phenomena happens, resulting in the aurora borealis, commonly known as the Northern Lights, which may be seen in the northernmost countries during the colder months.
But, Jupiter’s auroras are hundreds of times more intense than Earth’s, releasing hundreds of gigawatts of energy.
This energy from Jupiter’s north and south poles is so enormous that it could power every human for a short time.
After 40 years of research, a team led by University College London (UCL) and the Chinese Academy of Sciences in Beijing has figured out how auroras are generated.
The X-rays were caused by frequent oscillations in Jupiter’s magnetic field lines, which surround the planet in vertical loops connecting its north pole to its south pole, according to the researchers.
These vibrations produce plasma waves, which drive heavy ion particles “surfing” along magnetic field lines until they collide with the planet’s atmosphere, releasing massive amounts of energy in the form of X-rays.
In the scientists’ findings, X-ray bursts occurred every 27 minutes.
The charged ion particles that slam into Jupiter’s atmosphere come from huge volcanoes on Io, one of Jupiter’s 79 moons, spewing gas into space.
Due to collisions in Jupiter’s near environment, this gas becomes ionised, meaning its atoms are stripped of electrons, and forms the Io Plasma Torus, a doughnut ring of plasma encircling Jupiter.
“We have seen Jupiter producing X-ray aurora for four decades, but we didnt know how this happened,” said Dr William Dunn of UCL Mullard Space Science Laboratory. “We have seen Jupiter producing X-ray aurora for four decades, but we didnt know how this happened.”
They were only discovered after ions collided with the planet’s atmosphere.
“Now we know these ions are transported by plasma waves – an explanation that has never been proposed previously, despite the fact that Earth’s aurora is caused by a comparable process.”
Researchers coupled close-up observations of Jupiter’s environment by NASA’s Juno satellite – which has been orbiting our solar system’s biggest planet since 2016 – with simultaneous X-ray data from the European Space Agency’s XMM-Newton observatory, which is in Earth’s orbit.
For a total of 26 hours, these observations were carried out continually.
The scientists discovered a definite link between Juno’s plasma waves and X-ray auroral flares observed by X-MM Newton at Jupiter’s north pole.
The researchers next used computer simulations to show that the waves would propel the heavier particles into Jupiter’s atmosphere.
Professor Graziella Branduardi-Raymont said: “X-rays are normally created by highly powerful and violent events such as black holes and neutron stars, so it seems unusual that mere planets produce them as well.” Io, one of Jupiter’s 79 moons, is covered in volancoes spouting volcanic gas (NASA).
“We will never be able to visit black holes because they are beyond our ability to travel through space, yet Jupiter is right around the corner.”
Dr. Zhonghua Yao noted that comparable events are likely to be occurring around Saturn, Uranus, Neptune, and “possibly exoplanets as well” with the approach of the spacecraft Juno into Jupiter’s orbit.
Although the source of Jupiter’s magnetic field lines vibrating on a regular basis is unknown, there are speculations that the vibrations could be generated by solar wind or high-speed plasma flows within the planet’s magnetosphere (the area controlled by this magnetic field).
Jupiter’s magnetic field is 20,000 times stronger than Earth’s, implying a massive magnetosphere.
It would cover an area several times the size of Earth’s moon if visible in the night sky.
The new research was published in the scientific journal Science Advances.