Saturn has its rings, Mars has its rusty landscape, Earth has its whales, water, and wi-fi…and Jupiter has its Great Red Spot. The giant gas planet’s enormous orange storm—once over twice the diameter of Earth but today “only” about 1.3 times as wide—is one of the most distinctive planetary features in our Solar System. It’s so well-known that even young children are sure to include its orangey oval when drawing Jupiter!
But as famous as it is, there’s a lot we still don’t know about Jupiter’s giant storm. NASA’s Juno spacecraft, launched in August 2011, has now been orbiting Jupiter since July 4, 2016 and has been using its suite of science instruments to investigate the planet’s complex atmosphere like never before possible. Thanks to Juno, for the first time scientists are able to “see” deep below Jupiter’s dense clouds (in microwave wavelengths, that is) and find out what’s happening inside the GRS. What they’ve discovered is a storm hundreds of miles deep with a hot base that powers its winds.
On May 12, 2016, the Hubble Space Telescope captured a series of images of Mars and in them the planet’s moon Phobos can be seen appearing from behind the western limb. This was just 10 days before opposition which, in 2016, was the closest Mars had been to Earth since 2005, lending particularly good opportunity for picking out its largest—yet still quite small—moon.
Today, July 10 (July 11 UTC) NASA’s Juno spacecraft will make its first targeted flyover of Jupiter’s famous Great Red Spot since its arrival in orbit on July 4, 2016, getting our best look yet at the giant anticyclonic storm that’s been churning on the giant planet since at least 1830 (and possibly even since before 1665.)
Previous spacecraft (Voyager, Galileo, Cassini, New Horizons) have imaged the Great Red Spot but none from as close a distance as Juno will tonight. During P7—Juno’s seventh “perijove,” or closest point to Jupiter in its 53-day-long orbital path—Juno will pass over the GRS at an altitude of only about 5,600 miles.
Perijove (the point at which an orbit comes closest to Jupiter’s center) will be on Monday, July 10, at 6:55 p.m. PDT (9:55 p.m. EDT). At the time of perijove, Juno will be about 2,200 miles (3,500 kilometers) above the planet’s cloud tops. Eleven minutes and 33 seconds later, Juno will have covered another 24,713 miles (39,771 kilometers) and will be directly above the coiling crimson cloud tops of Jupiter’s Great Red Spot. The spacecraft will pass about 5,600 miles (9,000 kilometers) above the [Great] Red Spot clouds.
Once the flyover data is transmitted and received on Earth sometime on Friday, July 14 we can expect amateur image processors (myself definitely included!) to feverishly get to work bringing out as many details as possible in the raw data. (You can find raw images from Junocam and processed versions from the public here.) This, as they say, is going to be good!
Source/read more from NASA here: NASA’s Juno Spacecraft to Fly Over Jupiter’s Great Red Spot July 10
Today after almost 11 months in orbit the Juno team revealed the first scientific findings of the mission to the public via a NASA teleconference, giving us our first peek at the inner workings of Jupiter and how much of a surprise our Solar System’s largest planet is proving to be…which of course is quite fitting, as the spacecraft is named after the wife of Jupiter who could see through her mischievous husband’s veiling clouds.
“The new science results from Juno really are our first look close-up at how Jupiter works,” said Scott Bolton, principal investigator for the Juno mission. “For the first time we’re looking inside of Jupiter at the interior, and what we’re seeing is it doesn’t look at all like what we predicted.”
It’s all downhill from here! (Well not really, but it was for a little while when Opportunity was at the top of that hill!) The image above is a mosaic I assembled from six color-composites, each made from three separate images acquired in near-infrared, green, and near-ultraviolet color wavelengths on April 21, 2017 (mission sol 4707). It’s been adjusted to appear in approximate true color to what the scene might look like to a human standing on Mars. The view shows a ridge called “Rocheport” located on the western rim of Endeavour Crater (the interior of which would be toward the right in this image) which was the final segment of Opportunity’s last target region of exploration, Cape Tribulation. Opportunity’s wheel tracks can be seen at the bottom center, heading back up the ridge and zig-zagging toward the top (detail below).