Summary of “The Search for E.T. Will Almost Certainly Start with Eyeball Planets.”

Eyeball planets come in all sorts of flavors, depending on the conditions.
We are going to take a look at two examples: “Hot eyeball” and “Icy eyeball” planets.
A hot eyeball planet is located close to its star, on an orbit that makes it hotter overall than Earth.
So a hot eyeball planet’s thick night side ice cap spreads out and slowly flows toward the day side.
Icy eyeballs are also tidally locked to their stars, though their orbits are larger than those of hot eyeball planets, and heat is in short supply.
What icy eyeball planets do have is an abundance of water-the night side is covered in ice, and there is enough stellar heating at the substellar point for water to remain liquid.
Hot eyeball and icy eyeball planets are extreme cases, but any planet that is tidally locked to its star is likely to look very different on its day side and its night side.
The galaxy may be littered with wild varieties of eyeball planets! The search for life on other planets will almost certainly start with these worlds.

The orginal article.