Where did the water on Earth come from? To find out how Earth acquired all of its water, a team of researchers led by the University of California, Los Angeles (UCLA) looked at exoplanets. This investigation has the potential to advance knowledge of planetary creation and evolution. Scientists had to confine themselves to creating simulations of Earth’s birth and evolution within our own solar system prior to the discovery of exoplanets in the 1990s. Illustration by an artist demonstrating evolution, interactions with the hydrogen atmosphere, and the formation of liquid water.