in situ vs in place

in situ is an adjective but in place is not an adjective.

Word	Noun	Adjective	Verb	Adverb
in situ	No	Yes	No	Yes
in place	No	No	No	Yes

As adverbs, in situ and in place are synonyms defined as:

in situ (adjective)	in place (adjective)
being in the original position; not having been moved

in situ (adverb)	in place (adverb)
in the original or natural place or site	in the original or natural place or site
in position