Four hundred years after the discovery of Jupiter ’s Great Red Spot a pip of a different colour has been added , but its tarradiddle is a bit more complicated .
The first affair to know about the Great Blue Spot is that it does not emit or reflect lighter at around 450 nanometers , and therefore is not actually grim . Nor , despite our common association of blue with stale , is it related to Jupiter’sGreat Cool Spot .
Instead , the blue appears on map of the magnetic field . We ca n’t see magnetism , let alone in gloss , so a custom has evolved that north magnetic poles should be portrayed as red and south poles as blue . This has nothing to do with the uncommon sheath where magnetism does touch on color , such as when branding iron - oxide nanoparticles present arainbow spectrumdepending on magnetic field speciality .
The Great Blue Spot is magnetically very south, but is located near Jupiter’s equator.Image Credit: NASA/JPL-Caltech/SwRI/John E. Connerney
In the bar magnets many of us played with as children , this leads to a simple half - and - half marked with paint , but real - macrocosm magnetic fields are considerably more complex . mutation in field strength lend themselves to be shown in deeper or paler shades , as in the map of Jupiter ’s field below .
Notably , Jupiter ’s charismatic subject area is not like Earth ’s , where the north and south pole are almost directly opposite each other , with both comparatively close to the geographic pole . Even on Earth , there arestrange anomaly , but one of the first affair Juno revealed about Jupiter is that its field of force isstranger still , which turned out toinclude the Great Blue Spot .
The first preindication of this come in the concentrations of Second Earl of Guilford and south magnetic subject area divulge in the map above . With Jupiter’sGreat Red Spotbeing one of its most conversant and enduring features ( even if it has beenshrinking recently ) it was inevitable the south magnetic anomaly would be dubbed the Great Blue Spot .
As reported this week , the Great Blue Spot has anatmospheric jet associate with it , demonstrating that the magnetic field anomaly is shaping the giant planet ’s standard atmosphere . Exactly what is driving this rest unclear , but it does prove the Blue Spot matters .
The Great Blue Spot is also the place where Jupiter ’s magnetic field is changing the fast . Back in 2019 , Dr Kimee Moore of Harvard University said in astatement : " It is unbelievable that one minute charismatic spicy spot , the Great Blue Spot , could be responsible for almost all of Jupiter ’s secular mutant , but the numbers tolerate it out . "
The causes of the Great Blue Spot have yet to be fully explain . There is no exact match in the Northern Hemisphere , with a long magnetized banding instead and various other non - dipole neighborhood . This has at least salvage astronomers from needing to come up with a name that is n’t “ TheotherGreat Red Spot ” .
Jupiter ’s magnetic field is thought to be a consequence of the highly conductive sea of metal hydrogen at its core . Exactly what it is about the metal H that leave to such complexness high above is still a matter of venture . Even when the Galileo spacecraftplunged intoJupiter ’s atmosphere , it was never going to get remotely deep enough to garner answers before being crushed by the mighty pressure .
So far , two things we have find out about the Spot are that it is migrating eastward , and is associated withzonal windsaround 3,500 km ( 2,100 miles ) deep within the gun planet .
Explaining the pip is regard enough of a priority that it ’s the focus of six fly ball - bys inJuno ’s elongated missionalong with agreater focuson themoons .
