Earth-sized planets covered in water may be abundant around red dwarfs, the most common type of star in the Universe.

Yann Alibert and Willy Benz at the University of Bern used computer simulations to predict the properties of planets that could form around red dwarfs and host liquid water. They found that the radius of the planets would be 0.5–1.5 times that of Earth, with most being around the same size as Earth. More than 90% of the simulated planets were at least 10% water by mass, suggesting that they were completely surrounded by deep oceans.

The authors say that the prospects for life on such planets are unclear, because too much water could destabilize the climate.

Astron. Astrophys. in the press; Preprint at https://arxiv.org/abs/1610.03460 (2016)