1) An experiment showed that complex organic molecules could form in conditions similar to an interplanetary dust cloud and be transported to Earth via comets or asteroids, providing building blocks for life. 2) In 1952, the Miller-Urey experiment demonstrated that organic compounds like amino acids could form from inorganic substances thought to exist on the early Earth. 3) More recent experiments have shown similar complex organic molecules can form in icy mixtures in space when bombarded by radiation similar to cosmic rays.