The search for alien life hasn’t been a fruitful one yet. NASA and other space agencies have greatly improved their abilities to detect new exoplanets, but identifying distant planets is a long way from discovering the first evidence of life outside of Earth. Scientists have identified some signs that a few nearby bodies may have the ingredients necessary to support life, but so far it seems as if we’re all alone in our neck of the cosmic woods.
Still, the search continues for planets which lie in the “Goldilocks zone,” or circumstellar habitable zone if you’re not into the whole brevity thing. This area is the orbital region surrounding stars which is the perfect distance to support life – not too hot, not too cold. Astronomers frequently discuss finding Earth-like planets out of the assumption that our planet must somehow by the ideal type of world to support life.
However, a new theory proposed by astronomer Sean Raymond at the Laboratoire d’Astrophysique de Bordeaux in France says that perhaps we’re focusing too much on finding new Earths and we should turn our attention instead to discovering what he calls “eyeball planets.” These are a type of tidally locked planet, meaning the same side of the planet always faces towards its host star or planet. Raymond proposes that these orbits can result in two different types of eyeball-like planets in which there is a warmer side and a colder side. On a “hot” eyeball planet, the hot ‘pupil’ of the eye is composed of rock while the cold side is liquid; on a “cold” eyeball planet the ‘pupil’ is liquid while the dark side remains ice.
Raymond writes that the Milky Way “may be littered with wild varieties of eyeball planets” and that the search for alien life “will almost certainly start with these worlds.”
There is good reason to think that the first potentially life-bearing worlds that are now being detected around other stars probably look very different than Earth. Rather, these planets are more likely to look like giant eyeballs whose gaze is forever fixed on their host stars.
Raymond’s argument for prioritizing these types of worlds in our search for life is that “eyeball” planets can exist in a much wide range of circumstellar space than the Earth-like planets we seek out in stars’ Goldilocks zones. Thus, there could me many more of these eyeball planets out there in the universe than there are Earth-like planets, opening up further possibilities for discovering alien life.