Astronomers have long wanted to discover Earth-like worlds and according to new findings, there might be two exoplanets quite similar to our planet, with stable climates and axial tilts. One can only wonder if these distant worlds and Earth are really alike.
Two faraway worlds that may not be so alien
A recent study announced by the Georgia Institute of Technology at the end of June takes a look at some of these remote worlds, specifically at two exoplanets: Kepler-186f and Kepler-62f, whose stable climates and seasons are relatively similar to our planet. The first one has a similar size to Earth, being only less than 10 percent larger than it. It is found in the constellation Cygnus the Swan, some 500 light-years away, and it orbits within the habitable zone. The second object, Kepler-62f is part of the constellation Lyra the Harp, being found some 1,200 light-years away, and it is larger than Earth, by approx. 40 percent more.
Stable axial tilts
In order to determine the axial tilt of each of the two planets, the research team had to use computer simulations. The team was led by astronomer Gongjie Li and graduate student Yutong Shan. Based on the results that they found, they reached the conclusion that both exoplanets have stable axial tilts, which in turn means that they could have stable climates and normal seasons. What this means, evidently, is that the planets may be habitable, even though there are still other aspects to consider before reaching more definite conclusions.
We can take a look at both Earth and Mars in order to see just how important a stable axial tilt is. Our planet’s axial tilt had varied approx. every 10,000 years, only from 22.1 to 24.5 degrees, compared to Mars, whose unstable axial tilt has oscillated between zero and 60 degrees over the course of billion years. We can easily see why Mars now looks like a dry, cold desert. Another reason for this is the fact that, unlike Earth, the red planet does not have a moon to keep axial variations in check.
Potentially habitable worlds
When it comes to the two studied exoplanets, it is not known yet if they have any moons, but even if they did not have, based on this study, it looks like the objects’ spin axes “would have remained constant over tens of millions of years”, according to Gongjie Li. We definitely look forward to learning more about these two potentially habitable exoplanets. There are still other things to consider in the future, such as their composition, type of atmosphere and other factors.