Our Sun, like other stars, gives off gases called stellar winds which are known to play a key role in forming new stars and seeding new galaxies. Now it appears that these winds have another effect too: warming the atmosphere on planets like Jupiter.
Astronomers observed Jupiter’s auroras at its poles, like the Northern Lights here on Earth, which are caused by stellar wind. They found that the energetic particles of the solar wind interact with the planet’s atmosphere to create a heating effect.
“The solar wind impact at Jupiter is an extreme example of space weather,” James Sinclair, a researcher at NASA’s Jet Propulsion Laboratory (JPL) and leader of the research team, said in a statement. “We’re seeing the solar wind having an effect deeper than is normally seen.”
When solar wind hits Jupiter, the atmosphere and temperature of the planet are effected within just one day. The chemistry of the atmosphere changed and the temperature rose, as you can see in the heatmap image above. Around Jupiter’s poles are two bright spots indicating high temperatures, which is where the auroras are located.
The heat image was collected using the Subaru Telescope in Hawaii, operated by the National Astronomical Observatory of Japan. The telescope has an instrument called the Cooled Mid-Infrared Camera and Spectrograph (COMICS) which can record thermal images of the stratosphere.
These findings were unexpected because Jupiter is so large, but the effects of the solar wind still propagate very fast. “What is startling about the results is that we were able to associate for the first time the variations in solar wind and the response in the stratosphere — and that the response to these variations is so quick for such a large area,” JPL’s Glenn Orton, co-author and part of the observing team, said in the same statement.
The results are not only relevant to the study of Jupiter. They could shed light on the role of solar wind in changes in atmosphere and temperature on other planets and even inform understanding of our own planet’s history, according to Yasumasa Kasaba, researcher at Tohoku University and a member of the observation team: “Such heating and chemical reactions may tell us something about other planets with harsh environments, and even early Earth,” Kasaba said.