It’s no secret that I’m obsessed with Jupiter. To add to the mystery of the planet, researchers have found unexpected alternating currents going through the gas giant’s atmosphere.
Jupiter is the largest planet in our solar system. It boasts an aurora with a radiant power of approximately 100 terawatts, or 100 billion kilowatts. It’s the brightest aurora in the solar system and is centred around the planet’s poles.
A breathtakingly beautiful mystery
The data shows that electric currents passing through Jupiter’s magnetosphere, which produce auroras on Jupiter, have less direct current than what is expected. And it’s baffling scientists to no end.
One of the study’s co-authors, Professor Dr Joachim Saur from the Institute of Geophysics and Meteorology at the University of Cologne, said in a statement:
“These observations, combined with other Juno spacecraft measurements, show that alternating currents play a much greater role in generating Jupiter’s aurora than the direct current system.”
Enormous centrifugal forces
Like Earth, the auroras on Jupiter are oval rings near their poles and are driven by “a gigantic system of electrical currents that connects the polar light region with Jupiter’s magnetosphere,” the statement added.
However, whereas Earth’s currents are driven by direct currents, Jupiter’s are not. Saur added that Jupiter’s electric current systems are driven by “enormous centrifugal forces” in the planets rapidly rotating magnetosphere. He adds:
“Because of the planet’s fast rotation – a day on Jupiter lasts only ten hours – the centrifugal forces move the ionized gas in Jupiter’s magnetic field, which generate the electric currents.”
He explains that the volcanically-active moon Io produces one ton of sulfur dioxide gas per second; which ionizes into Jupiter’s magnetosphere.
Barry Mauk of the Johns Hopkins University Applied Physics Laboratory observed signatures of powerful electric potentials, aligned with the gas giant’s magnetic field, and explains:
“At Jupiter, the brightest auroras are caused by some kind of turbulent acceleration process that we do not understand very well. There are hints in our latest data indicating that as the power density of the auroral generation becomes stronger and stronger; the process becomes unstable and a new acceleration process takes over. But we’ll have to keep looking at the data.”
What is the Juno Cam?
Juno is in a “highly-elliptical 53-day orbit around Jupiter. Each orbit includes a close passage over the planet’s cloud deck; where it flies a ground track that extends from the planet’s north pole to its south pole.”
Juno is fitted out with a Steller Reference Unit (SRU), and the JunoCam. The SRU collects engineering data for navigation purposes, while the JunoCam imager shares Jupiter’s beauty with the public.
The Juno Cam passes over both of Jupiter’s polar regions every 53 days and found that direct current was approximately 50m amps, not as high as theoretical models would suggest, according to Live Science.