Even the giant Jupiter, with its vortex superstorms and unstable temperatures, has a soft side. A team of researchers has recently documented stellar winds from the Sun that compress the planet’s magnetosphere and raise temperatures in the planet’s atmosphere by 300 degrees Fahrenheit (150 degrees Celsius).
The team’s study, published today in the journal Geophysical Research Letters, is the first to document this phenomenon – a surge of solar energy reaching Jupiter. Scientists believe that solar strikes occur several times a month.
“We found that Jupiter’s upper atmosphere responds globally – and quite dramatically – to compression by the solar wind,” said James O’Donoghue, a planetary scientist at the University of Reading in the UK and lead author of the paper, in an email to Gizmodo. “The rapid flow of the solar wind crashed into Jupiter’s magnetosphere, which acts like a giant magnetic bubble repelling the solar wind, causing intense auroral activity that dumps heat into the atmosphere.”
The atmosphere around Jupiter’s poles then expanded, creating a heat wave across the planet that was about 12 times the diameter of the Earth. According to O’Donoghue, the team was able to detect this event using data from the Keck II telescope and measurements made by the Juno spacecraft over Jupiter, which was “in the right place at the right time” to witness the event.
“Juno was in Jupiter’s magnetosphere until the great squeeze (as I call it), after which the compressed boundary suddenly took Juno outside the magnetosphere. O’Donoghue added that astronomers have only observed similar heating on Earth – albeit on a much smaller scale.
“It could also be happening on Saturn, Uranus, or Neptune, but we haven’t seen it yet,” O’Donoghue said. – It’s a rare event, though… the compression can reach Jupiter and Jupiter. “It’s a rare event… compression like this can reach Jupiter (or any other planet) about a couple times a month, depending on solar activity.”
“Our solar wind model correctly predicted when Jupiter’s atmosphere would be disturbed,” said Matthew Owens, a researcher at the University of Reading and co-author of the paper, in a university release. “This helps us to better understand the accuracy of our forecasting systems, which is essential to protecting Earth from hazardous space weather.”
The study indicates that planetary atmospheres, including that of the largest planet in the Solar System, may be more sensitive to the behavior of their host stars than previously known.
In our solar system, flares from the Sun can change the atmospheric dynamics of large planets, generating winds that move energy between worlds.
This work is also a reminder of how dynamic our Sun is, and how many processes in the solar system remain poorly understood. More observations of both our host star and the planets in the solar system will help scientists understand not only our solar system as an ecosystem, but also how similar – or unique – our system is to other star systems and exoplanets in the universe.
