The Great Red Spot of Jupiter is about twice the size of Earth and has tumbled in the planet's atmosphere for at least 350 years.
Despite astronomers' long-standing interest in it, however, it's mysterious: It's hundreds of millions of miles away, and only a handful of spacecraft have taken detailed images of it.
That will all change on July 10 — when the space agency's Juno probe will fly within a cosmic breath of the Great Red Spot and take its closest-ever images of the super-storm.
Juno, a robot the size of a basketball court, settled into orbit around Jupiter on July 4, 2016.
But Juno has yet to take close-up photos of the Great Red Spot because Jupiter rotates rapidly, about once every 10 Earth hours. The probe's visits are also fast and infrequent — about every 53.5 days — to avoid exposure to the monstrous planet's electronics-damaging radiation.
Juno will fly too close to the storm — about 5,600 miles above it — to capture the whole thing in one view at that point. Making the task even more challenging, the probe will zoom by at 34 miles per second, which is speedy enough to traverse the continental US in a little more than a minute.
Once all of JunoCam's raw photo data is verified, processed into full color, and stitched together as a giant mosaic image of the probe's flyby, it will be unrivaled in history.
The first report of a feature on Jupiter which could be the Great Red Spot was about 350 years ago, not long after the first telescopic observations from Galileo.
It is possible the feature has existed considerably longer but there are no recorded observations to provide evidence.