Scientists are usually optimistic when they find exoplanets situated in the habitable zones in their stars. This means they are at the optimal distance that allows water to exist in a liquid state, making it theoretically possible for life to exist. However, if their axes are tilted and their orbits strange, they might enter a snowball state.
Is the position of an exoplanet enough to tell if it’s habitable?
There are many factors that might influence the habitability of an exoplanet. One of them is its position from its parent star, but researchers have discovered more factors that influence it. The position of their axis and their orbit might be one of them, so they decided to see what happens if the two are tilted.
The main objects of many studies have been those exoplanets as close to their stars as Earth is to the Sun. Now, researchers wanted to see how a tilted axis can influence their habitability. They used to think those planets with a bigger tilt became warmer. Now, a recent study has revealed they actually cause a snowball state.
A tilted axis and an irregular orbit might plunge it into a snowball state
Whenever the planet with the tilted axis performs an irregular orbiting movement, it becomes a lot more likely for it to enter such a snowball state. If this happens, then any water present on it would freeze and it would be impossible for life to exist. This new hypothesis became apparent after researchers performed more advanced simulations.
In some cases, these irregularities might lead to the apparition of ideal temperatures for life. However, this can happen extremely rarely, and the snowball state hypothesis is a lot more common. Researchers also say that an ice age on an exoplanet would come out as a lot more severe than on Earth. This means that chances of finding life are getting more and more slim.
This study shows the position of an exoplanet is not enough to establish its habitability. The shape of its orbit and the angle of its axis are just as important, and they are often the decisive factor in this matter. The paper in question should soon appear in the Astronomical Journal, but it’s currently available on arXiv.
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