An international team of researchers has discovered that Jupiter, the largest planet in the Solar System, also has austral auroras (south) and that, against all odds, they act independently of the northern ones (Borealis), according to a study published in Nature Astronomy.
Researchers from ESA and NASA have discovered that unlike Earth’s polar lights, the intense auroras seen at Jupiter’s poles unexpectedly behave independently of one another. Jupiter’s northern auroras are erratic and “do not coincide in behavior, neither in intensity nor in frequency with those found on Jupiter’s southern pole”
Auroras are planetary phenomena that take place when the wind of energetic particles of a star collides with the magnetic field of a planet (magnetosphere).
Using ESA’s XMM.Newton and ANSA’s Chandra X-Ray space observatories, astronomers were able to observe high-energy X-Rays produced by the auroras on each of Jupiter’s poles.
Experts found that the southern auroras on Jupiter pulse every 11 minutes consistently, while those at the planet’s northern pole flared chaotically.
“These auroras don’t seem to act in unison like those that we’re often familiar with here on Earth,” says lead author William Dunn of University College London’s Mullard Space Science Laboratory, UK, and Harvard-Smithsonian Center for Astrophysics, USA.
“We thought the activity would be coordinated through Jupiter’s magnetic field, but the behavior we found is really puzzling.
“It’s stranger still considering that Saturn – another gas giant planet – doesn’t produce any X-ray auroras that we can detect, so this throws up a couple of questions that we’re currently unsure how to answer.
“Firstly, how does Jupiter produce bright and energetic X-ray auroras at all when its neighbor doesn’t, and secondly, how does it do so independently at each pole?”
This finding raises numerous questions about how auroras occur through the universe. Interestingly, Jupiter’s independently pulsing auroras indicate that astronomers have a long way to go in order to understand how the planet itself produces some of its most energetic emissions, reports the European Space Agency.
“Charged particles have to hit Jupiter’s atmosphere at exceptionally fast speeds in order to generate the X-ray pulses that we’ve seen. We don’t yet understand what processes cause this, but these observations tell us that they act independently in the northern and southern hemispheres,” adds Licia Ray, from Lancaster University, UK, and a co-author.
Future studies of Jupiter’s auroras will help shed light on the phenomena produced on the gas giants poles.
In the next two years, astronomers are planning on more X-Ray observational campaigns using XMM-Newton and Chandra, and observations from NASA’s Juno spacecraft, which started orbiting Jupiter in mid-2016.
In addition to the above, ESA’s Juice Spacecraft will arrive at Jupiter by 2029, and will investigate not only the Gas giant atmosphere and magnetosphere, but will also observe its auroras and the effect they cause on the Galilean Moons.
“This is a breakthrough finding, and it couldn’t have been done without ESA’s XMM-Newton,” adds Norbert Schartel, ESA project scientist for XMM-Newton.
“The space observatory was critical to this study, providing detailed data at a high spectral resolution such that the team could explore the vibrant colors of the auroras and figure out details about the particles involved: if they’re moving fast, whether they’re an oxygen or sulfur ion, and so on.
“Coordinated observations like these, with telescopes such as XMM-Newton, Chandra and Juno working together, are key in exploring and further understanding environments and phenomena across the Universe, and the processes that produce them.”