Quote FaceDeer (

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Do you know of any papers that have been published regarding the possibility of visible light emissions from radiation belts like this?
I didn't find any documentation about this, it was just a wild speculation. The Universe is inmense, maybe things like this appear in some places if it is possible for some concrete circumstances. I think visible plasma emissions from exoplanets is not something well studied maybe because of the lack of scientific interest on something that specific by now. But maybe someone could make the calculations and see if this is reasonably rigorous. Maybe a plasma trapped in the radiation belts can't be visible because it would never get so dense (maybe there could be an accumulation mechanism) or so hot as to glow in the visible range, or maybe yes, I don't know.
Exotic worlds have to be taken into account but always with realism as you said (the greatness of Space Engine is the reliability of those depictions).
Quote FaceDeer (

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I was tempted to mention something about how Io spews out interesting streams of charged particles and how that might be visible under some extreme circumstances in this post
Maybe we should discuss this in the other thread. But I agree completely that this is a fascimating issue. In fact there is a real visible glow on Io created by those extreme currents. This image was taken in the visible range by the cameras of the Galileo spacecraft on May 31, 1998, from the night side of Io:
The glow comes from charged particles in the radiation belt of Jupiter smashing the surface and atmosphere of this body. The green glow corresponds to sodium, red from oxigen and the blue glow comes from the interaction with volcanic gases.
If Jupiter had a gaseous belt in the same region wouldn't it glow like Io? or it's unstable? By now we can only assure that Io lights up because of this phenomena. It would be an awesome feature for Space Engine.
Either way, Io and other moons have a great electric influence on Jupiter aurora's because of electric discharges. The discharge spots are even visible in the polar regions opf the planet:
Quote FaceDeer (

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Aurorae on planets with multi-polar magnetic fields
Wow, I don't want to be a pain in the neck but I asked for exactly that on this thread: http://en.spaceengine.org/forum/21-11-48054-16-1420670037
Martian auroras are visible in the UV frequencies because of the atmospheric composition of the planet but indeed I found very important to add those strange auroral structures on Space Engine to show multipolar magnetic fields on alien planets. Maybe an extremely magnetized mountain could have its own auroral structure in the skies.
Quote FaceDeer (

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Phosphorescence in surface minerals on airless worlds that are subject to high radiation environments.
Wow, we trully are soulmates or something because I have been calculating the last week the posibility of finding such worlds. I will post the details in a new thread one day soon. Mineral phosphorescence could be quite noticiable with some specific parameters (for example in the surface of bodies located quite far away from Blue Giants and Wolf Rayet stars). Soon I will post, soon...