The Miller-Urey experiment showed that simple molecules could have arisen abiotically. This chemical experiment included conditions similar to those present on the early Earth, and tested the origin of life under those conditions.
Water (H2O), methane (CH4), ammonia (NH3) and hydrogen (H2) were the chemicals used to produce the results of the experiment, the factors needed for simple life to arise. Given similar conditions on other planets, it's possible that life could arise there as well.
