undiscoverable vs unascertainable

undiscoverable and unascertainable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
undiscoverable	No	Yes	No	No
unascertainable	No	Yes	No	No

As adjectives, undiscoverable and unascertainable are synonyms defined as:

undiscoverable and unascertainable: not able to be ascertained; resisting discovery

undiscoverable (adjective)	unascertainable (adjective)
not able to be ascertained; resisting discovery	not able to be ascertained; resisting discovery