You've heard of different types of planets - hot giants, gas giants, icy planets, exoplanets and even rogue planets. But have you heard about something stranger called eyeball planets?
Eyeball planets are the ones which kind of look like a giant eyeball, with both the hemispheres looking completely different from each other. The way they orbit around their star results in all the deserts lying on one side of the planet while all the ice on the other. It can also have rings of various climates resembling the pupil, iris and white of an eye.
The eyeball-like appearance of the planet is linked to tidal locking, meaning it takes exactly the same time to rotate as it takes to orbit. Or in other words, the duration of a day and a year on such planets is the same. That means one side of the planet always faces its star while the other always has it face away from the star.
For example, the Moon is tidally locked to the Earth, which is why we can see only one side of the Moon at all times. But Earth isn’t tidally locked to the Sun; exactly why we have a day/night cycle. However, being tidally locked, on eyeball planets one side is in perpetual day with temperatures reaching up to 100ºC or more, and the other in perpetual night being as cold as less than -100ºC.
According to scientists, these planets are more common than previously thought, and they might even be habitable at the narrow ring where the 2 hemispheres meet, but under certain conditions of course!
Well even if these planets are habitable, life over there would not be anything similar to living on Earth. The sun would never move in that ring and you would witness sunset forever. Due to the huge temperature difference, winds would constantly blow around the planet upto thousand km/h.
Since eyeball planets are more likely to orbit a red dwarf, plants will receive less light than they receive here on Earth. They’ll have to make use of all the possible light they get, and overtime they might even evolve to be black as black absorbs all colours of the visible spectrum.
Scientists are actively looking for habitability on such planets, and with the next generation of telescopes coming in, we might even get a step closer.