Water World Artist Concept

This artist's concept shows a hypothetical planet covered in water around the binary star system of Kepler-35A and B.

In a 2017 study in the journal Nature Communications, researchers investigating the climates of exoplanets determined that this hypothetical planet could be habitable, depending on its distance from the two stars. On the far edge of the habitable zone, the hypothetical water-covered planet would have a lot of variation in its surface temperatures. But closer to the stars, near the inner edge of the habitable zone, the global average surface temperatures on the same planet would stay almost constant.

https://photojournal.jpl.nasa.gov/catalog/PIA21470