Aurorae are caused when charged particles stream along the magnetic field of a planet and into its atmosphere. On Earth these charged particles come from the solar wind – a stream of particles that emanates from the Sun. Variations in the Sun control the frequency and intensity of these beautiful displays that can also herald problems – such as interference with satellite communications and power distribution.
On Jupiter however, the dominant source of particles is its own moons, particularly Io which throws out roughly one tonne of volcanic material every second. Some of this becomes ionised (plasma) and is pulled in Jupiter’s magnetic field. It co-rotates in a plasma sheet around the planet, but as the particles spread out the magnetic field weakens and this breaks down causing the particles to crash into Jupiter’s atmosphere creating an aurora.
On Saturn, whilst one aurora had been observed, the primary source of the particles was unclear. RCUK Academic Fellow Tom Stallard, of the University of Leicester explains “At Saturn, scientists were unsure whether the aurora was caused by the solar wind or by particles from its own system. When we discovered the second zone of aurorae on Saturn, we realised this aurora, unlike the one already seen on Saturn, was behaving in the same way as Jupiter’s, largely unaffected by the solar wind, dominated by the rotation of the planet.”
Modelling the aurorae on Jupiter and Saturn shows that both exhibit aurora in the positions where the co-rotation between the planet and its plasma sheet breaks down.
Stan Cowley of the University of Leicester said, “We can now say that some of Saturn’s aurorae are like Jupiter’s and they have a common formation process. Further, our discovery of the secondary aurora on Saturn suggests that we shall also find one on Jupiter within its polar region.”
This research is drawn from data collected by NASA’s InfraRed Telescope Facility. Saturn’s main aurora has been studied using the NASA/ESA Hubble Space Telescope.
The UK researchers have been funded by the Science and Technology Facilities Council, the Engineering & Physical Sciences Research Council and Research Councils UK.
Julia Short | alfa
Breaking the optical bandwidth record of stable pulsed lasers
24.01.2017 | Institut national de la recherche scientifique - INRS
European XFEL prepares for user operation: Researchers can hand in first proposals for experiments
24.01.2017 | European XFEL GmbH
A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Physics and Astronomy
24.01.2017 | Life Sciences
24.01.2017 | Health and Medicine