Jupiter’s magnetic field is truly unique, reveals a new study just published in the journal Nature. The gas giant, the biggest planet in our solar system, not only has the strongest magnetic field of all the other planets, but also the most unusual one.
“We find that Jupiter’s magnetic field is different from all other known planetary magnetic fields,” the authors wrote in their paper, based on recent observation made by NASA’s Juno spacecraft.
While Earth and Saturn have magnetic fields that resemble a bar magnet, with the magnetic flux emerging from the north pole and traveling across the planet to return to the south pole, that of Jupiter is a lot more complicated and actually looks even stranger than those of Neptune and Uranus — messy, weaker magnetic fields mirroring several crisscrossed bar magnets.
What makes Jupiter’s magnetic field one-of-a-kind is that it seems to suffer from a case of “split personality,” reports Science News, boasting a non-dipolar northern hemisphere and an utterly dipolar southern hemisphere. More to the point, in Jupiter’s case the magnetic flux springs out from a narrow band near the north pole and returns to two separate spots instead of just one.
One of these spots is located in the proximity of the south pole, whereas the other one is found south of the planet’s equator and has been dubbed the Great Blue Spot — in relation to the south pole of a bar magnet, often imaged in blue.
This means that Jupiter’s magnetic field essentially has one north pole and two south poles, notes Popular Mechanics.
We should not be surprised that we are surprised to discover just how strange and wonderful our own cosmic backyard is.https://t.co/7EIKlgvQkn
And our solar system is just one infinitesimal point in a probably infinite universe.
— mark keightley (@cool_aardvark) September 5, 2018
According to study lead author Kimberly Moore, a Ph.D. student at Harvard University in Cambridge, Massachusetts, the magnetic field around Jupiter is “a baffling puzzle.”
Its “hemispheric dichotomy,” as Gizmodo puts it, is more than surprising considering that, before Juno started orbiting Jupiter in 2016, astronomers believed the planet’s magnetic field was very similar to that of Earth.
Mapping Jupiter’s Magnetic Field
Until Juno began its scientific mission in the gas giant’s system, “our best maps of Jupiter’s field closely resembled Earth’s,” said Moore, who added that: “We were baffled at first, since the field Juno was showing us was nothing like we expected.”
Her team used Juno data to map Jupiter’s magnetic field at four separate depths, starting from the planet’s surface and working their way toward the interior. This led to the discovery of the narrow band at the planet’s north pole, as well as of the Great Blue Spot — unrelated to Jupiter’s iconic Great Red Spot, a massive hurricane that has been raging south of the planet’s equator for more than 3.5 centuries, the Inquisitr previously reported.
“Within Jupiter, most of the flux emerges from the dynamo region in a narrow band in the northern hemisphere, some of which returns through an intense, isolated flux patch near the equator. Elsewhere, the field is much weaker,” the scientists explained in the paper.
— Gizmodo (@Gizmodo) September 5, 2018
These findings “complicate our picture of Jupiter’s interior,” said Moore, because they suggest that the planet could have a much more intricate internal structure than previously anticipated.
Possible Explanations For Jupiter’s Eccentric Magnetic Field
In order to explain the bizarre shape of Jupiter’s magnetic field, the researchers speculate that the gas giant’s core was subjected to extreme pressure and incredibly high temperatures. This could have made the hydrogen gas within the planet’s interior turn into liquid metallic hydrogen and become as electrically conductive as the molten metals that generate Earth’s magnetic field — a fluid layer of iron, nickel, and other metals wrapped around our planet’s inner core and measuring 1,242 miles in diameter, the Inquisitr previously reported.
As a result, Jupiter’s core “might have dissolved, and mixed with the inner half of the planet,” creating a convoluted magnetic field, said Moore.
Another possibility is that the mixture of hydrogen and helium which makes up Jupiter’s composition may have given rise to helium rains inside the planet, which “could alter the magnetic field,” she pointed out.
“Jupiter’s winds might also reach down to depths where there’s sufficient electrical conductivity to affect the field,” Moore described a third possible scenario.
Additional Juno observations could help settle the matter once and for all. The basketball court-sized spacecraft is scheduled to continue studying Jupiter until 2021, the Inquisitr recently reported, and is expected to beam back even more data on the gas giant’s peculiar magnetic field.
“There’s a lot more data to collect, so hopefully there will be more things to investigate,” said Moore. “The internal structures we propose are speculative. One, or multiple, or none could be true.”