Super-Earths with atmospheres far from their star may be habitable

What they found: The study, published in the journal Nature Astronomy, used modeling to find that super-Earths — rocky worlds that are larger than our own — could support thick atmospheres that would allow water to persist on their surfaces even if they're far from their star.

• The idea is these planets would have formed with a primordial atmosphere — which Earth also had early in its history but eventually lost — that would keep the world temperate for about 8 billion years, depending on the thickness of the atmosphere.
• “What we found is that in many cases, primordial atmospheres were lost due to intense radiation from stars, especially on planets that are close to their star. But in the cases where the atmospheres remain, the right conditions for liquid water can occur,” Marit Mol Lous, an author of the study said in a statement.
• "[W]here sufficient geothermal heat reaches the surface, radiation from a star like the Sun is not even necessary so that conditions prevail at the surface that allow the existence of liquid water.”

The big picture: Scientists are particularly interested in finding planets like Earth in orbit around Sun-like stars, but they aren't easy to find.

• Current technology isn't able to pick out exact "Earth twins" yet, so this kind of study broadens the scope of what a habitable planet might look like and what next-generation telescopes could focus on.

Go deeper: How to tell if an exoplanet is habitable