Even rarer, Wolf 1069 b orbits in its solar system's "habitable zone," meaning a special region where liquid water can exist on the surface.

A weird quirk: Like the moon, Wolf 1069 b is "tidally locked" in its orbit, meaning the same side is constantly facing the red dwarf star.

So, if you stood on the star-facing side of Wolf 1069 b, a year would last about 16 days, the sun wouldn't set, gravity might be similar to that on Earth, and you might even find water sloshing over the surface.

They looked for tiny but periodic changes in light from the star, a technique called the "radial velocity method."

That makes it a rare finding, and an exciting planet candidate to study for biosignatures, which are evidence of past or current life.

"Because of its favourable prospects regarding habitability, it is among a small illustrious group of targets, such as Proxima Centauri b and TRAPPIST-1 e, to search for biosignatures," the Max Planck Institute for Astronomy noted.