ascension vs mounting

ascension and mounting both are nouns.

Word	Noun	Adjective	Verb	Adverb
ascension	Yes	No	No	No
mounting	Yes	No	No	No

As nouns, mounting is a hyponym of ascension; that is, mounting is a word with a more specific, narrower meaning than ascension:

ascension: a movement upward; rise above the ground
mounting: an event that involves rising to a higher point (as in altitude or temperature or intensity etc.)

ascension (noun)	mounting (noun)
the act of changing location in an upward direction	framework used for support or display
a movement upward; rise above the ground	an event that involves rising to a higher point (as in altitude or temperature or intensity etc.)
(astronomy) the rising of a star above the horizon