Galactic origin of life. Artist's impression of a red, alien planet and molecules in interstellar space representing the complex organic chemicals needed for the origin of life. The alien planet is orbiting a Sun-like star (at upper left). The planet has swirling clouds in its atmosphere, suggesting that it may have the gases and water needed to sustain life. The cratered appearance of the planet suggests that these chemicals may have fallen to its surface in meteorites. From lower left to lower right stretches a Milky Way, the limb of a spiral galaxy. Complete spiral galaxies are seen at bottom.