NASA's Juno spacecraft completed perijove 7 yesterday, flying nearest to Jupiter in its 53-day orbit and collecting intimate science a mere 5600 miles above the gas giant's cloud tops. This flyby took the spacecraft directly over Jupiter's Great Red Spot, a centuries-old, 10,000-mile-wide vermilion vortex that has long perplexed scientists. Among the storm's unknowns are its depth and perpetuating forces. The first raw images of the Earth-sized hurricane were released today.
"This is a storm that we've been tracking ever since the dawn of modern astronomy, and we're the first generation to get this exquisite level of detail," Leigh Fletcher, a planetary scientist at the University of Leicester, tells Mental Floss. He says that from the spacecraft's perspective, the Great Red Spot would have stretched from horizon to horizon.
Juno has thus far given us a startling new vision of Jupiter—one of teeming teals and swirling storms—and caused scientists to sharpen their pencils and rewrite much of what they knew about the solar system's largest planet. Today's initial image data promise no less a revolution in the scientific understanding of Jupiter.
What does the Great Red Spot look like from an expert's perspective? "I see a swirl of red cloud material as the vortex spirals anti-clockwise, a deep-red heart that coincides with the calm center of the powerful winds, and clusters of small-scale clouds that stand above the red depths," says Fletcher. "There's even evidence of waves in the spiral arms in these breathtaking images. It's an incredible level of detail in an image that's set to become instantly iconic."
Today's image release is just a taste of what is to come, of course. The spacecraft had all nine of its science instruments active during the pass, and data are being blasted back to the Deep Space Network at the speed of light. "For me, the real science always starts with spectroscopy," says Fletcher, "assessing the fingerprints of the gaseous composition and aerosols that are present within the storm." Juno's science payload allows scientists to peer hundreds of miles beneath Jupiter's clouds. "For years we've tried to understand how deep [the Great Red Spot] penetrates into the atmosphere, and what might be sustaining it. By probing below the clouds with the microwave instrument, we might just find the answers we've been looking for."
The Juno spacecraft launched on August 5, 2011 and achieved orbit around Jupiter on July 4, 2016. The next flyby of Jupiter will take place on September 1. It will mark the spacecraft's eighth orbit and seventh science flyby.
Want to see more amazing images? Head over to NASA's JunoCam.