Astrobiology is a relatively new scientific field and seeks to answer basic questions about life in the universe. What are the physical properties of our universe that make life as we know it possible? How did life on Earth arise? How might life arise other places in the universe and what might it be like? How can we search for life on other planets?
In the late 1960s and 1970s a field emerged called exobiology, which was intended to be the study of extraterrestrial life. But because at least so far, there are no known examples of life beyond the Earth, it became clear that this field needed to be a subcategory of a broader discipline. Astrobiology, in contrast, is the study of questions about the relationship between life, and the chemistry and physics of the universe. Astrobiology, so far, focuses mainly on life on Earth, since it is the only example of life we have. Its goal is to understand these relationships in the broad context of life in the universe.
Image credit: Alice Hopkinson, LCO