Jupiter’s Great Red Spot is not only gigantic, but also super deep

Using the Juno spacecraft’s keen eye, researchers have unraveled that Jupiter’s famed storm may be as deep as 500 kilometers.

Planet Jupiter is known for its colorful bands and giant, swirling storms. The most famous storm—perhaps even the most famous in the entire solar system—is the Great Red Spot; a gigantic anticyclone that has raged on the gas giant for hundreds of years. In a new study, researchers have taken a closer look at these and a host of other storms using the Juno spacecraft. And that leads to some interesting discoveries.

Juno’s microwave radiometer (MWR) allows researchers to peer beneath Jupiter’s turbulent cloud tops and study the structure of its numerous storms. The most famous of these storms is the iconic anticyclone known as the Great Red Spot. This red-colored vortex, which is even wider than the entire Earth, has intrigued scientists since it was discovered nearly two centuries ago.

Earth compared to Jupiter’s Great Red Spot. Image: JunoCam Image data: NASA/JPL-Caltech/SwRI/MSSS; JunoCam Image processing by Kevin M. Gill (CC BY); Earth Image: NASA

Gigantic and deep

The Great Red Spot is known to be gigantic. For example, the storm is big enough to observe it with telescopes from Earth. However, researchers are now discovering that many of Jupiter’s storms also go very deep. Some extend to at least 100 kilometers deep. And the Great Red Spot? It even reaches between 350 and 500 kilometers deep.

Surprising discovery

It means that this famous storm is not only very large, but also very deep. This surprising discovery shows that the storms cover areas beyond where water condenses and clouds form, extending below regions where sunlight warms the atmosphere. The height and size of the Great Red Spot also means that the concentration of atmospheric mass in the storm may be detected by instruments studying Jupiter’s gravitational field.

Cyclones

In addition to the new knowledge that researchers have now gained about the Great Red Spot, Juno is also giving us insight into the other storms that are raging on the gas giant. “Previously, Juno surprised us with evidence that the phenomena in Jupiter’s atmosphere extend deeper than expected,” said study researcher Scott Bolton. “Now we’re starting to put these separate pieces together and, for the first time, we’re getting a real understanding of how Jupiter’s beautiful and violent atmosphere works — in 3D.” For example, the results show that the cyclones are warmer at the top, with lower atmospheric densities, while they are colder at the bottom, with higher densities. Anticyclones – which spin in the opposite direction – are actually colder at the top but warmer at the bottom.

Tyres

In addition to cyclones and anticyclones, Jupiter is covered in thick red, brown, yellow and white clouds that wrap around the planet. The way they are organized makes it look like Jupiter is ‘striped’. Strong east-west winds moving in opposite directions separate these beautiful bands. Juno previously discovered that these winds, or jet streams, reach as deep as 3,200 kilometers. But researchers are still trying to explain exactly how these jet streams form. Data collected by Juno’s MWR during multiple flybys now provides a possible clue: the ammonia gas in the atmosphere is moving up and down in remarkable alignment with the observed jet streams.

The new findings from NASA’s Juno probe provide a more complete picture of Jupiter’s distinctive and colorful atmospheric features and the workings of the invisible processes beneath the dense cloud cover. The results highlight the inner workings of the belts and cloud zones surrounding Jupiter, expanding our knowledge of the polar cyclones and even the Great Red Spot. “These new observations open up a treasure trove of new information about Jupiter’s puzzling observable features,” said study researcher Lori Glaze.