Astronomers weekly announce the discovery of new exoplanets, some similar in size or temperature to our planet –- but Earth-like worlds are not always far away.

Though Saturn's largest moon, Titan, is a small, cold world orbiting on the outskirts of the solar system, it actually boasts many familiar features.

“Titan is fascinating because it has some surprising properties so similar to Earth,” said planetary scientist Oded Aharonson from the California Institute of Technology. “It has a liquid which erodes channels, an atmosphere, a hydrologic cycle, and many other parallels.”

Chief among...