On Earth, bursts of particles spewed by the Sun spark shimmering auroras, like the Northern Lights, that briefly dance at our planet’s poles. But, on Jupiter, there’s an auroral glow all the time, and new observations show that this Jovian display sometimes flares up because of a process having nothing to do with the Sun.
Jupiter watchers have long known that the giant planet’s ever-present polar auroras – thousands of times brighter and many times bigger than Earth – are powered by both electrically charged particles from the Sun colliding with Jupiter’s magnetic field and a separate interaction between Jupiter and one of its many moons, called Io.
In this artist’s rendering, flows of electrically charged ions and electrons accelerate along Jupiter’s magnetic field lines (fountain-like blue curves), triggering auroras (blue rings) at the planet’s pole. Accelerated particles come from clouds of material (red) spewed from volcanoes on Jupiter’s moon Io (small orb to right). Recent observations of extreme ultraviolet emissions from Jupiter by satellite Hisaki (left foreground) and the Hubble Space Telescope (right) show episodes of sudden brightening of the planet’s auroras. Interactions with the excited particles from Io likely also fuel these auroral explosions, new research shows, not interactions with particles from the Sun.
Credit: Japan Aerospace Exploration Agency
But there are also auroral explosions on Jupiter, or periods of dazzling brightening, similar to auroral storms on Earth, that no one could definitively trace back to either of those known causes.
In the aurora-making interaction of Jupiter and Io, volcanoes on the small moon blast clouds of electrically charged atoms (ions) and electrons into a region surrounding Jupiter that’s permeated by the planet’s powerful magnetic field, thousands of times stronger than Earth’s.
Rotating along with its rapidly spinning planet, the magnetic field drags the material from Io around with it, causing strong electric fields at Jupiter’s poles. The acceleration of the ions and electrons produce intense auroras that shine in almost all parts of the electromagnetic spectrum but most brightly in high-energy bands, like ultraviolet light and X-rays, that are invisible to unaided human eyes.
Now, new observations of the planet’s extreme ultraviolet emissions show that bright explosions of Jupiter’s aurora likely also get kicked off by the planet-moon interaction, not by solar activity.
A new scientific paper about these observations by Tomoki Kimura of the Japan Aerospace Exploration Agency (JAXA), in Sagamihara, Kanagawa, Japan, and his colleagues, was published online today in Geophysical Research Letters, a journal of the American Geophysical Union.
Starting in January 2014, a telescope aboard the JAXA’s Hisaki satellite, which focused on Jupiter for two months, recorded intermittent brightening of the giant planet’s aurora. The telescope detected sudden flare-ups on days when the usual flow of charged particles from the Sun, known as the solar wind, was relatively weak.
Additional space and ground-based telescopes, including the Hubble Space Telescope, also viewed Jupiter during these lulls in the solar wind. Both Hisaki and Hubble witnessed explosions of the planet’s aurora despite the solar wind’s calm, suggesting that it’s the Jupiter-Io interaction driving these explosions, not charged particles from the Sun, according to the new study. The new research does not address exactly what is happening in the Jovian magnetosphere to cause the temporary brightening of auroral explosions.
The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 60,000 members in 139 countries. Join the conversation onFacebook, Twitter, YouTube, and our other social media channels.
+1 (202) 777-7524
Peter Weiss | American Geophysical Union
Further reports about: > American Geophysical Union > Geophysical > Geophysical Research > Geophysical Research Letters > Hubble Space Telescope > JAXA > Japan Aerospace Exploration Agency > Jupiter > Sun > explosions > ions and electrons > magnetic field > observations > powerful magnetic field > solar wind > ultraviolet > ultraviolet light
Sea ice extent sinks to record lows at both poles
23.03.2017 | NASA/Goddard Space Flight Center
Less radiation in inner Van Allen belt than previously believed
21.03.2017 | DOE/Los Alamos National Laboratory
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences