as·tro·bi·ol·o·gy 
(ăs′trō-bī-ŏlə-jē)
(ăs′trō-bī-ŏlə-jē)n.
The scientific study of the possible origin, distribution, evolution, and future of life in the universe, including that on Earth, using a combination of methods from biology, chemistry, and astronomy.
as′tro·bi′o·logi·cal (-ə-lŏjĭ-kəl) adj.
as′tro·bi·olo·gist n.