From the Daily Mail, a report on a theory that tidally locked planets might offer the best hope for finding evidence of extra-terrestrial life.
A hot eyeball planet is located close to its star, on an orbit that makes it hotter overall than Earth.
The day side would be roasting with any water boiling into vapour, while the night side would be freezing.
But at the terminator - the boundary between night and day – conditions could be just right for life to thrive.
Icy eyeballs have orbits that are larger than those of hot eyeball planets. While they may have huge amounts of water, there is not enough heat for it to be liquid.
But in an area called the 'substellar point' there may just been enough sunlight to form a liquid pond.
Scientists believe that underwater life could exist in the subsurface ocean, and also by the icy shore of a pond.
The idea of an eyeball Earth was triggered by the detection of an exoplanet called Gliese 581g about 20 light-years away - which may be the first known potentially habitable alien world.
In 2013, researchers at Columbia University looked at the parameters of the ice flow and melt, and whether that band of water left in the middle could be maintained.
'No matter how efficient you are at trapping water on night side, there always has to be some water on the dayside,' Dr Kristen Menou said.
Accordingly, small pockets of habitability might remain in these water-trapped worlds.
Red dwarves make up approximately three quarters of the stars in the galaxy, making the existence of some of these planets orbiting them much more likely.