re: Space is extremely fascinating because....
"so much remains to find out, to explore."
The same could be said about your stomach.
There are no end of stuff which could be extremely fascinating without including space.
There are unique significances regarding space that
enhance one's fascination- it's big, and it is more ancient
than earth. It contains the story beginning of earth and the ending of earth. Etc.
If space aliens ask earthlings 10,000 years from now, why
earthing never left their cradle, will the answer be because space is extremely fascinating?