Despite the amazing biodiversity of our planet and the variety of habitats in which life is found, Earth is the only place in the Universe that we know life has arisen. That is not to say that life does not exist elsewhere. We don’t know if life is common or rare even in places with Earth-like conditions. Or perhaps having an Earth-like planet is unnecessary and different kinds of life are likely to originate in different circumstances.
The fact that life arose on Earth just 100 million years (a relatively short time in geological terms) after the end of the Late Heavy Bombardment suggests that life is likely to appear where the conditions are right. Alternatively, some scientists think that the early presence of life on Earth means that life may have come from space. Astrobiology, the study of the origin, evolution, and distribution of life in the Universe, brings together biologists, chemists, astronomers, and other scientists to investigate some of the deepest mysteries in science: the search for our own origins and the answer to the question, “Are we alone?”