Actually, in my comment, when I typed "supre" I was thinking "super". I can't recall coming across supre in DuoLingo yet. (And, if I did, I am sure I confused it with super. Kind of like theater versus theatre or meter versus metre.)
- Super is a preposition and supre is an adverb.
- Both mean "above", while supre can also mean "upstairs".
- The examples sentences don't seem to support a difference between the two related to touching. For example:
La luno kaj la steloj brilis super ni. The moon and stars were shining above us.
La steloj briletas supre. The stars are glittering above.