This storm has been raging for at least 350 years, and soon humanity will get its first close-up look.
On Monday NASA's Juno spacecraft, in orbit around Jupiter since last July, will fly over the planet's giant storm, dubbed the Great Red Spot, taking high-definition photos and making scientific observations.
"We're finally going to fly directly over that spot, and we're going to get our first close-up look at it," Scott Bolton, Juno's principal investigator from Southwest Research Institute, told CBC News.
"When we are screaming past at our closest approach point we're just a few thousand miles above it."
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Juno's orbit around the biggest planet in our solar system takes roughly 53 days. Most of the time the spacecraft is far from Jupiter, but on one of those 53 days, Juno flies extremely close to the massive planet, travelling from the north pole to the south pole around 24,000 km/h in just under an hour.
'It's like a piece of art'
Though the Great Red Spot is the oldest storm in the solar system, it's also shrouded in mystery. It's been around for hundreds of years, but it could have existed many years before humans turned a telescope to the heavens.
'When you get really close, it's really amazing. It's like a piece of art.' - Scott Bolton, principal investigator, Southwest Research Institute
The mechanism of the storm — what feeds it and has allowed it to exist for many generations — is unknown. And over the years, the storm hasn't been stable: some years it brightened or shrank, only to begin growing again. Now, recent data suggest that the storm is again shrinking and getting paler.
"We don't know what we'll see. Of course, we've never seen it this close before … When you get really close, it's really amazing," Bolton said. "It's like a piece of art. We will see things that we've never seen before."
Instruments on the spacecraft will collect data on the storm's structure, cloud tops, temperature, colours and more. They will even look for lightning.
But engineers are likely to be holding their breath. Each orbit takes Juno on a different path, and each time it gets more dangerous as it passes through the planet's incredible radiation, which could damage the orbiter. That concerns Bolton, who says, "I'm always at the edge of my seat."
But it's worth it.
He's not only excited about the visual treat that awaits us all, but he's also anticipating discoveries that will keep scientists on Earth busy for years.
"We don't know what the Great Red Spot really looks like or even how it works," Bolton said. "This is the largest storm in the solar system. This is it. This is the king. The king planet and the king storm."
Juno was set to be closest to the planet at 9:55 p.m. ET July 10, a mere 3,500 kilometres above the cloud tops. Then, just more than 11 minutes later, it was expected to be 9,000 kilometres above the raging storm, every instrument pointing towards it.
Citizens could beat scientists
Something that's unique to this planetary mission is that the raw images captured by JunoCam aboard the spacecraft are put online when they are downloaded. Here, ordinary citizens are able to take the data — which doesn't give a complete, pretty picture like you may imagine — put it together and create full-colour photographs.
Some attempt to make it as realistic as possible, but some creative licence is also allowed. Most often you can find photos enhancing some colour or features on the planet.
But Bolton said that's part of the excitement of this next flyby. As soon as his group gets that data, they plan to put it on the site where anyone can process the image. Of course, his team will also be working on it.
Still, there's a possibility that someone from the public will beat them to it. Bolton will ensure that the image is scientifically accurate and, if it is, will release it to the public, likely by the following weekend.
"Somebody next week is going to be sitting at a computer, and they're going to be the very first human in all of history to see what the Great Red Spot looks like really close-up," Bolton said.
Bolton is anticipating the images because other regions of the planet have proved to be beautiful and unique.
"In my wildest dreams, I wouldn't have guessed how stunning the images that we've already returned from other parts of Jupiter. A lot of them are breathtaking, and you realize wow, this thing really is a beautiful planet."