No image of Jupiter is complete without showing a big red smudge on it. This smudge is Jupiter’s Great Red Spot, a tremendous storm which has been raging for centuries on end.
The storm has been in the news in the last few days as a spacecraft has just made the closest pass over it of any spacecraft that has visited Jupiter.
This feature of Jupiter is perhaps one of the most spectacular phenomena in the solar system.
The Great Red Spot is larger than the entire Earth itself. All the continents, the oceans, the weather systems, all the energy on Earth combined does not match the immense size of this enormous storm. The amount of energy inside this storm is really not something that human beings can comprehend – there is so much energy that it really just becomes a number. There is nothing on Earth that can even be remotely compared to it.
The storm is so big that when a smaller storm gets close to it, it gets absorbed and becomes part of the Great Red Spot, adding its energy to it.
The storm was first noticed centuries ago, perhaps even as far back as the 17th century. It is reasonable to assume that the storm had existed for long before then as well. No one can say for certain why the storm has lasted for so long, or even why it is red.
The Juno spacecraft orbiting Jupiter made its closest pass over the Great Red Spot on 11 July 2017, passing about 9000km from the cloud tops. This is far, far closer than any other spacecraft has been to the storm.
The images taken are stunning.
Many more images taken by the Juno spacecraft can be found here.
This storm will not last forever. It is steadily shrinking. The storm is currently about 16,000km across – observations by the Voyager 1 and 2 spacecraft in 1979 showed it to be over 23,000km across.
Historical observations showed the spot to be much larger than this – observations from the 1800s showed the storm to be over 40,000km across. This is large enough to fit over three Earths end to end.
The storm is on its way to becoming a circle. Perhaps within our lifetimes, the storm will dissipate away. But, given Jupiter’s incredibly turbulent atmosphere, maybe by that point there will be a new great storm.