Jupiter's enormous magnetic field and its rapid rotation around its axis cause an aurora that is a thousand times stronger than similar light shows on Earth
Avi Blizovsky
The researchers looking towards the planet Jupiter with the Hubble Space Telescope recently got to see a spectacular dance of the beauty of aurora high in the atmosphere. Similar to what happens on Earth, Jupiter's polar mountain is a product of radiation from space hitting the planet's magnetic pole.
"Now that we have been able to pinpoint the general location of the auroral 'curtains' in Jupiter, and have been able to map their daily changes, we may also be able to discover the reason for their occurrence." says John T. Clark, a member of a team of scientists who have been studying the northern lights phenomenon at both poles of Jupiter for two years.
The images from the Hubble provide enough detail to allow Clark and his colleagues to track the daily changes in the aurora borealis and fluctuations. They found that the changes in brightness occur during a sidereal day (of about 10 earthly hours), apparently as a result of the compression of the magnetic field on the side of the planet facing the sun; And also that the patterns for the pita of light are fixed on the surface of the planet and move along with it.
To the general view provided by Hubble are added the close-up photographs and the magnetic field measurements carried out by the Galileo spacecraft orbiting Jupiter. By comparing them, scientists hope to refine theories about how Jupiter creates and maintains its fiery electrical light shows. The results of their research appear in the latest issue of "Science".
The latest Hubble observations simultaneously show the poles surrounded by a luminous "curtain" as well as an elliptical ring that goes out into space and connects the poles of Jupiter at an angle of about 10 to 15 degrees. The observations proved that there is a connection between the aurora borealis and the passage of volcanic material with a strong electrical charge of about a million amperes, which regularly passes between Jupiter's volcanic moon - Io - and Jupiter.
Auroras are created when charged particles (such as electrons, protons and positive ions) are trapped in the magnetic field surrounding the planet. These parts fall towards the magnetic poles in the south and north, and collide with molecules and atoms in the upper layer of the atmosphere. The atoms accumulate energy as a result of the collision, and release some of it in the form of light (just as the fluorescent gas in neon lights glows when an electric current is passed through it.)
On Earth, the glow at the poles is created as a result of a stream of charged particles coming from the sun. Rightly so, due to its distance from the sun, the pressure of these particles is indeed smaller, but the planet's enormous magnetic field, and its rapid rotation around its axis (one rotation every ten hours) results in the creation of an aurora that is a thousand times stronger than the light shows of the Earth.
The volcanic material that is emitted also plays a role in the process of creating the aurora borealis. Scientists believe that the volcanic emissions throw particles into space that become charged and increase their radiation and are captured in Jupiter's huge magnetic field and participate in the process.
It is still not clear which is more influential, the processes driven by the Sun or the exchange of matter with Io, and how exactly they create the aurora borealis. "The diameter of each aurora on Jupiter is between one thousand and two thousand kilometers," says Clark. degrees Celsius. The aurora borealis would pass over it from east to west at a speed of 6,000 kilometers per second, because Jupiter's rapid rotation would leave it below the slower moving Io."
Clark and his colleagues hope that future observations will provide more information about Jupiter's aurorae phenomenon. The team shared the information they had with the scientists who operate the Galileo spacecraft, which moves towards Jupiter's magnetic field, orbits the planet and studies the large moons. The spacecraft can record the types of charged particles in the field, their location and their energy level. With the help of the information, the scientists hope to create a more up-to-date picture of the charged particles that create the aurora borealis and of their source - the moon Io.
Bulletin of the Space Telescope Science Center, 1996
At that time, the Hidan site was part of the IOL portal from the Haaretz group, the article was published by me when I was working for the Haaretz newspaper, and among other things I wrote columns in the space section within the section pages in part B of the newspaper.
Published in "Haaretz" - space section around 20/10/1996 (exact date unknown, does not appear in the Ha'aretz archives. The photo of Tzedek in any case on the Haval website is from 17/10/1996.
