Whether a planet is habitable or not depends on it being present in the habitable zone of its star. In the habitable zone, a planet is present at a safe distance from the star such that it is neither too hot nor too cold. This helps the planet keep its atmosphere intact, and most importantly retain water on its surface.

When astrophysicists search for a habitable planet, they look for the planets that are present in the habitable zones. However, a recent study shows that the planet does not necessarily have to be present in the habitable zone to retain its atmosphere. The airborne dust can also be factor behind a planet being habitable.

In a series of simulations performed, planets were made to orbit around stars. When they orbited around the stars, they were not made to spin on their own axis. This way one of their sides faced the star the entire time while the other one faced away. In other words, one side had the daytime all along whereas the other one had a night time.

With the research at hand up till now, the side that faced the stars all the time was supposed to heat up immensely and the night side was supposed to cool down rapidly, hence deteriorating the planet’s atmosphere. however, such was not the case, instead, the atmospheric temperature stayed optimal. This was partly because of the airborne dust. The airborne dust kept the planets’ dayside cool and the nightside warm. This phenomenon is known as negative climate feedback. This way the planets retained their atmosphere.

In simpler terms, dust helps to lock in the temperature of the planet.

Airborne dust has widened the scope of research for the astrophysicists in their hunt to find a planet that could host life. Up till now, they had only been searching for planets that orbited in the habitable zones. However, airborne dust conceals other signs of life that one might find on a habitable planet, such as traces of oxygen and water vapors.

Source: https://doi.org/10.1038/s41467-020-16543-8