A guide to Jupiter's Great Red Spot
Facts about Jupiter's Great Red Spot and images of the centuries-old cyclone.
Jupiter's Great Red Spot is a huge storm in Jupiter's Southern Hemisphere that's about 1.3 times as wide as planet Earth.
It is a giant oval storm of whirling clouds that travel anticlockwise, with wind speeds reaching up to 680 kilometres per hour: much faster than any of Earth's storms.
Scientists got their best ever look at the storm when NASA's Juno spacecraft flew over the Great Red Spot on 10 July 2017.
During the flyover, Juno passed about 9,000 km above the Great Red Spot’s cloud tops.
Data collected by NASA's Juno spacecraft has revealed that the Great Red Spot penetrates at least 320km down into Jupiter's atmosphere. That's over 30 times deeper than the deepest point of Earth's oceans.
How old is the Great Red Spot?
The Great Red Spot is known to have been raging for centuries, having been observed by astronomers for over 300 years.
Astronomers Robert Hooke and Giovanni Cassini are known to have observed and recorded a feature located on Jupiter at the Great Red Spot's latitude, suggesting they may have also observed the huge cyclone.
But the first confirmed sighting of the Great Red Spot is thought to have been by German amateur astronomer Samuel Heinrich Schwabe in 1831.
How big is the Great Red Spot?
Observations of the Great Red Spot have shown that it is shrinking over time.
The Voyager spacecraft recorded the width of the Great Red Spot as around 25,000km in 1979 - about twice the diameter of Earth - and it's now thought to have shrunk to 16,000km, as of April 2017.
Data from ground-based telescopes reveals that the Great Red Spot has reduced in width by a third and height by one eighth since the time of the Voyagers' fly-by.
Pictures of the Great Red Spot
There are plenty of amazing images of the Great Red Spot captured by the Juno spacecraft and the Hubble Space Telescope over the years.
Below is a selection of images of the Jovian storm captured by astrophotographers and BBC Sky at Night Magazine readers.
For advice on capturing images of Jupiter yourself, read our guide on how to photograph the planets.