Originally posted by Robbert Raets
Shouldn't it be Astrii Nostrae, the academy motto being 'Ex Astris (from the stars) Scienta'?
well, almost.

'astrii' means 'to commit one's self to'

I think you're looking for astri or astris.

and both stellis and astris are correct; it's a matter of subtle connotation. stellis is the plural of star; astris is also the plural of star, but it can also refer to a constellation.

So, it would be similar to the difference between 'the stars' and 'the heavens' in English.

A matter of poetry, really.

-Robert