In your SpaceEngine directory, there should be a folder called 'Docs'.
You open the console with '~' (tilde). (On a keyboard with German umlauts, it's 'ö'.)
This will take you to mount Denali in Alaska. (Formerly Mount McKinley.)Select Earth
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LandTo 63.069167 -151.007778 200
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I do not know what shader addons you found, but addons belong usually in the 'addons' folder.
There is a fairly hazy definition between what astronomers consider a 'super-earth' and a 'mini/sub-neptune'. Many in fact wouldn't consider there even being a difference. Officially, a super-earth is any terrestrial planet from 2.5 to about 8 Earth masses. Usually super-earths are rocky, but as I mentioned above, the line between a super-earth and a mini-neptune (or 'gas-dwarf' - which is any planet that has a mass of LESS THEN 10 Earth masses) is very obscure to the point of being non-existent. The problem is of course that we can't actually study exoplanets of this mass directly and so can only infer such details with various measurement techniques.
I myself answered a similar question from another user, starting HERE.