Observations with the Subaru Telescope, a Japanese 8-m telescope on Mauna Kea, Hawaii, show that the aurorae at Jupiter’s poles are heating the atmosphere of the gas giant, and that it is a rapid response to the solar wind.
Aurorae at Earth’s poles occur when the energetic particles blown out from the Sun, the solar wind, interact with and heat up the gases in the upper atmosphere.
The same thing happens at Jupiter, but the new observations show the heating goes 2-3 times deeper down into its atmosphere than on Earth, into the lower level of Jupiter’s stratosphere (upper atmosphere).
Understanding how the Sun’s outpouring of solar wind interacts with planetary environments is key to better understanding the nature of how planets and their atmospheres evolve.
What is startling about the results is that scientists were able to associate the variations in the solar wind and the response in Jupiter’s stratosphere, and that the response to these variations is so quick for such a large area.
Within a day of the solar wind hitting Jupiter, the chemistry in its atmosphere changed and its temperature rose, the astronomers found.
Such heating and chemical reactions may tell us something about other planets with harsh environments, and even early Earth.
The results appear in the journal Nature Astronomy.
NASA’s Juno spacecraft, currently orbiting Jupiter, took a dramatic image of the gas giant earlier this month.
The color-enhanced image comes from Kevin M. Gill, a NASA software engineer who moonlights as one of the Juno’s amateur image processors, shows a large circular storm trailed by clouds swirling in a jet stream in Jupiter’s northern hemisphere.
Juno has been in a highly elliptical orbit around Jupiter since 2016. The spacecraft captured the image on Feb 12, during its 18th close pass of the planet. Juno was just 8,000 miles above Jupiter’s cloud tops at the time.
First launched in 2011, Juno took five years traveling to Jupiter from Earth. The mission seeks to map Jupiter’s interior and determine how much water is inside the planet, among other goals. Scientists hope that by studying Jupiter, they will have a better understanding of how the planets formed.
NASA makes raw images from Juno available to the public online. The agency encourages amateur astrophotographers to download and enhance the images before uploading them back to Juno’s website. Dozens of space enthusiasts have participated, some by simply cropping the images and others by performing advanced color reconstruction or highlighting a particular atmospheric feature of the planet.
NASA plans to end Juno’s mission in July 2021, at which point the spacecraft will self-destruct in the most metal way by hurling itself into Jupiter.