Researchers from the Georgia Institute of Technology carried out a new study on Kepler-186f, an Earth-like exoplanet located at 500 light years away. According to this study, this Earth-like exoplanet is more like the Earth than expected.
An Earth-like exoplanet is a term used to describe an Earth-sized planet habiting outside our solar system that’s orbiting its host star within the so-called habitable zone, a region of a solar system that satisfies the temperature and star radiation conditions for life to develop. However, in the case of Kepler-186f, the similarities to the Earth are many, besides size and position within its solar system.
Researchers from the Georgia Institute of Technology employed spin axis dynamics simulations and analysis on Kepler-186f and found out that this exoplanet’s axis is tilted in about the same angle as the Earth and is stable. This discovery is hugely important because a planet’s axis tilt is what makes possible the existence of seasons and different climates, just like on Earth.
The Kepler-186f Earth-like exoplanet is more similar to the Earth than previously expected
The scientists made a comparison between Kepler-186f, Mars, and Earth. Accordingly, Mars turned from a “wet” planet into a deserted red globe because of its axial tilt which is very unstable even though the planet is within the habitable zone of our solar system.
“Mars is in the habitable zone in our solar system, but its axial tilt has been very unstable, varying from zero to 60 degrees. That instability probably contributed to the decay of the Martian atmosphere and the evaporation of surface water,” said Assistant Professor Gongjie Li, the new study’s leading author.
On the other hand, Earth presents a more stable axial tilt that oscillates between 22.1 and 24.5 degrees once every 10,000 years.
As for the Kepler-186f, the scientists observed that the planet is not interacting with the other four planets in its solar system as it happens with Earth and Mars for example. Despite this fact, this Earth-like exoplanet has a spin axis that remains stable for millions of years, and that indicates this planet can have seasons and different climates, in a very similar way to the Earth.
“Our study is among the first to investigate climate stability of exoplanets and adds to the growing understanding of these potentially habitable nearby worlds,” concluded Li.