Scientists using NASA’s Hubble Space Telescope have produced new maps of Jupiter using annual “portraits” of the giant planet to determine changes to its features, especially its mysterious Great Red Spot.
The observations also capture a broad range of other features, including winds, clouds, other storms and atmospheric chemistry.
“Every time we look at Jupiter, we get tantalizing hints that something really exciting is going on,” said Amy Simon, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
“This time is no exception.”
The new images confirm that the giant storm called the Great Red Spot has continued to shrink and become more circular. It is now 24,000 kilometres wide with winds of around 530 kilometres per hour. It is also more orange than it was.
NASA also reports that scientists have located an elusive wave In Jupiter’s North Equatorial Belt. It that had been spotted on the planet only once, decades before, by Voyager 2.
In those images, the wave is barely visible, and nothing like it was seen again, until the current wave was found traveling at about 16 degrees north latitude, in a region dotted with cyclones and anticyclones. Similar waves – called baroclinic waves – sometimes appear in Earth’s atmosphere where cyclones are forming.
“Until now, we thought the wave seen by Voyager 2 might have been a fluke,” said co-author Glenn Orton of NASA’s Jet Propulsion Laboratory in Pasadena, California. “As it turns out, it’s just rare!”
He believes the wave may originate in a clear layer beneath the clouds, only becoming visible when it propagates up into the cloud deck.
In addition to Jupiter, the researchers have observed Neptune and Uranus, and maps of those planets also will be made public shortly. Saturn will be added to the series later.
You can access the Outer Planet Atmospheres Legacy program images and data at https://archive.stsci.edu/prepds/opal/