Sketches by the French-Italian astronomer Giovanni Cassini (1625-1712) of the planet Jupiter, showing its Great Red Spot (upper centre of each image). In both images, North is at bottom. The left sketch was made in January 1672, and the right one in July 1677.
A Hurricane twice the size of Earth.
Over the years there have been many theories about Great Red Spot, what it is, what causes it and how the system may develop in the future, but scientists have now got a settled view of the phenomenon.
A persistent high-pressure system located within the hydrogen atmosphere of Jupiter, 22 degrees south of Jupiter’s equator, has produced the anti-cyclonic storm twice the size of Earth. Often likened to a hurricane, the storm has winds which blow counter clockwise around the centre at up to 268 miles per hour, and according to regular observations made since 1831, combined with initial observations in the 17th century, has been raging for at least 300 years. But the Great Red Spot is more than just a surface level feature, more recently, The NASA Juno spacecraft detected strong evidence that the feature was responsible for gravity variations, which tugged on the space craft as it passed overhead. These variations were sufficiently large to allow scientists back on Earth to create a 3D image of the storm, showing it to extend down to at least 350km below the uppermost cloud layer.
Why is it red?
It was not only the size of the feature that helped early astronomers identify it, but its distinctive red colour helped too. There are several theories as to why the spot is red, and importantly no definitively understood explanation, but one of the most widely held hypotheses is that it’s due to the unique ammonia rich make-up of Jupiter’s atmosphere, and hundreds of years of solar radiation.
Jupiter’s atmosphere is made up of layers of different gasses and compounds. The uppermost layer is Ammonia, under that is a complex compound called ammonium hydrosulphide and then under that is a layer of water clouds. Whilst all three of these layers would normally have pale white clouds – of the kind seen in bands circulating around the planet, the mixing of them together, especially in something as intense as hurricane twice the size of Earth, combined with high energy solar radiation, splits the ammonium hydrosulphide into more complex granular compounds, which also have a red colouration.
Whether or not this is correct may never be known, and scientists may be running out of time to find out.
A temporary feature?
Whilst the Great Red Spot is not the only storm on Jupiter, it is by far the largest – but hundreds of years of constant observation have shown that it has grown and shrunk in size often. Currently in a shrinking phase, in April 2017, the storm measured 10,159 miles (16,350 km) wide, approximately a third the size observers noted in the 1800s, recent observations taken by Hubble have shown that it is currently at its smallest size in at least 150 years. There is also no sign of the Great Red Spot reversing this trend any time soon.
In a NASA statement from 2018, Reta Beebe, an emeritus professor at New Mexico State University said,
"There is evidence in the archived observations that the Great Red Spot has grown and shrunk over time, however, the storm is quite small now, and it's been a long time since it last grew.”
Editors note: Skip to 1:18 in the video for Starship glory
Not quite, whilst it is certainly a possibility that the Great Red Spot could vanish entirely long before 2402 (and the events of Picard Season 3 episode 10), Jupiter is already brewing brand new storms around its equator for her to hide in and plan the assimilation of Starfleet with Changeling help. What looked like the Great Red Spot on the screen, could just have been a brand new storm, with a similar size and colouration, that takes its place in the future - keeping the story intact.
What did you think of this article, do you think the Great Red Spot will vanish in the next few decades? Let us know in the comments below.
WRITTEN BY WoorLord -
EDITED BY Solace
IMAGES SOURCED FROM NASA/ESA/A. Simon (Goddard Space Flight Center), and M. H. Wong (University of California, Berkeley) and the OPAL team - Science Photo Library - outpost-vfx.com - news.sky.com
