space biology vs astrobiology

space biology and astrobiology both are nouns.

Word	Noun	Adjective	Verb	Adverb
space biology	Yes	No	No	No
astrobiology	Yes	No	No	No

As nouns, space biology and astrobiology are synonyms defined as:

space biology and astrobiology: the branch of biology concerned with the effects of outer space on living organisms and the search for extraterrestrial life

Other synonyms of space biology include exobiology.

space biology (noun)	astrobiology (noun)
the branch of biology concerned with the effects of outer space on living organisms and the search for extraterrestrial life	the branch of biology concerned with the effects of outer space on living organisms and the search for extraterrestrial life