Scientists peer into the depths of Jupiter's great red spot

NASA's Juno mission to Jupiter has yielded some very interesting results about the planet's great red spot. Juno was launched in 2011 and arrived at Jupiter in 2016 and has been observing the massive storm using microwave and gravity-based instruments to peer into its structure.

Juno goes deep

The great red spot is a superstorm in the Jovian atmosphere 16 thousand kilometres wide, a greater diameter than that of the entire Earth.  Astronomers believe the Great Red Spot has been active for several hundred years, but little was known about its depth until recent observations from Juno.

One of the goals of the Juno mission was to try to understand if storms like the GRS exist only in the upper part of the planet's atmosphere, or if they go deeper.

A tale of two studies

Scott Bolton, Vice-President of the Southwest Research Institute in San Antonio, Texas, and Principal Investigator of the mission, made use of Juno's microwave radiometer to study the storm. It allowed for a look below the cloud top and found that the GRS goes down at least 320 kilometres. 

A second investigation measured the gravitational field signature of the Great Red Spot to also try to understand the storm's depth. This data found that the depth of the GRS could not possibly be more than about 500 kilometres.

The two studies, then, were able to determine a minimum and maximum depth for the GRS. According to Bolton the depth of the storm suggests something other than the sun's heat entering the Jovian atmosphere is powering the storm. 

Although it is the most iconic storm in the entire Solar System, it is one of many, perhaps hundreds of storms in the atmosphere of Jupiter. Bolton says that it is these storms that give the gas giant Jupiter a similar look to that of a Van Gogh painting. The reason for the colour red, however, is still a mystery.

Produced and written by Mark Crawley