Warm Up Before Monday’s Flyby With These Cool, New Views Of Jupiter’s Red Spot

Here’s a view of the Great Red Spot (white) you’ve probably never seen before. It’s a composite color infrared image of Jupiter reveals haze particles over a range of altitudes, as seen in reflected sunlight. We sense infrared light as heat, but it’s as much a form of light as the rest of the colors of the rainbow. This particular band of infrared picks up high clouds and hazes in Jupiter’s atmosphere. The Great Red Spot (GRS) appears very bright, revealing that it’s one of the highest-altitude features in Jupiter’s atmosphere. The orange-yellow in Jupiter’s polar regions comes from the reflection of sunlight from high-altitude hazes that are products of the aurora’s interaction with Jupiter’s upper atmosphere. The hook-like feature off the left side of the GRS and the delicate wave flow pattern in the clouds to its right are being stretched by the intense winds within the Red Spot. Credit: Gemini Observatory/AURA/NSF/JPL-Caltech/NASA

In just 3 days, NASA’s Juno spacecraft will fly directly over Jupiter’s Great Red Spot, a 10,000-mile-wide (16,000 km) storm that’s been whirling around the atmosphere for possibly 400 years or more. While the Voyager and Galileo spacecraft have taken photos of the planet’s most iconic feature, Juno will come closer than any before it, flying just 5,600 miles (9,000 km) above the Spot on July 10.

“Jupiter’s mysterious Great Red Spot is probably the best-known feature of Jupiter,” said Scott Bolton, principal investigator of Juno. “This monumental storm has raged on the solar system’s biggest planet for centuries. Now, Juno and her cloud-penetrating science instruments will dive in to see how deep the roots of this storm go, and help us understand how this giant storm works and what makes it so special.”

This true color mosaic of Jupiter was constructed from images taken by NASA’s Cassini spacecraft on December 29, 2000, during its closest approach to the giant planet at a distance of approximately 6.2 million miles (10 million km).  Credit: NASA/JPL/Space Science Institute

This will be Juno’s sixth science flyby of Jupiter. It will reach perijove, its closest to the planet, Monday, July 10 at 8:55 p.m. CDT when it zooms just 2,200 miles (3,500 km) above the cloud tops. 11½ minutes later it will cruise directly over the Great Red Spot. All eight of the spacecraft’s instruments as well as its imager, JunoCam, will be on during the flyby.

Back in May, the Gemini North telescope on Mauna Kea on the big island of Hawaii took high-resolution photos of Jupiter in different infrared colors (wavelengths) of light to support the Juno mission and uncovered a curious swirling structure in the Spot’s inside, a hook-like feature on its western side and a beautiful, feathery wave extending off its eastern side.

Like the colors of the rainbow, infrared light doesn’t just come in one “color” but many. At longer infrared wavelengths, Jupiter glows with thermal (heat) emission. In dark areas, thick clouds block the emission from the deeper atmosphere. The Great Red Spot is visible just below center. Credit: Gemini Observatory/AURA/NSF/UC Berkeley

The Gemini telescope uses special filters that detect specific colors of light than can penetrate the upper atmosphere and clouds of Jupiter. It also uses advanced “adaptive optics” to  remove distortions from turbulence in the Earth’s atmosphere and produce extremely high-resolution images. In adaptive optics, the telescope’s main mirror is continually flexed as if were a rubber sheet (it’s not, it’s glass but still flexible) to compensate for the turbulence in the air that would otherwise distort and blur objects photographed through the telescope.

It’s an amazing image and reminds us that each color of light unpeels a new layer of Jovian surprises. Stay tuned for more next week.