Prospective spacefarers can scratch Kepler-438b off their list of alien world destinations as the exoplanet has been proven to be too inhospitable to support life.
In a study featured in the journal Monthly Notices of the Royal Astronomical Society, researchers at the University of Warwick have discovered that Kepler-438b is located near a star that regularly blasts the Earth-like exoplanet with high-energy superflares every few hundred days.
While it is doubtful that these superflares on their own provide too much of an impact on the habitability of Kepler-438b, the researchers believe they can cause far-reaching effects when combined with massive plasma explosions called coronal mass ejections (CMEs).
These two occurrences may make it difficult for any form of life to establish itself on the exoplanet.
"Large coronal mass ejections have the potential to strip away any atmosphere that a close-in planet like Kepler-438b might have, rendering it uninhabitable," Chloe Pugh, one of the authors of the study, explained.
Scientists have found that even though the exoplanet only takes around 35 days to complete its orbit, it is still considered to be within the "habitable zone" because its red dwarf star is relatively cooler and dimmer compared to the solar system's own sun.
Pugh also pointed out that the insufficient atmosphere on Kepler-438b leaves it more susceptible to ultraviolet (UV) and charged particle radiation coming from the superflares, both of which can be devastating to life forms.
The researchers note that if Kepler-438b had global magnetic fields much like Earth does, it may be able to retain an atmosphere of its own.
However, if the exoplanet does not possess such magnetic fields, or if the superflares prove to be too powerful, it is likely that it could lose any atmosphere it may have and become too irradiated to even sustain life.
Other Known Exoplanets that Resemble the Earth
Kepler-438b may no longer be a viable location for alien life forms in the universe, but there are other planets beyond the solar system that may have just the right elements to be a cradle for life.
Kepler-186f
Kepler-186f is considered to be the first Earth-like exoplanet ever to be spotted within the habitable zone of the red dwarf Kepler-186. Located around 490 light-years from Earth, this rocky planet is about 10 times larger than our own world.
HD 85512b
Revealed in 2011, this exoplanet is one of 50 such worlds discovered through the use of Chile's High Accuracy Radial Velocity Planet Searcher (HARPS). HD 85512b is 3.6 times larger than the Earth and can be found approximately 35 light-years from Earth.
Gliese 581d
With a distance of only 20 light-years away from Earth, Gliese 581d is one of the closest exoplanets relative to our planet's location. It is also seven times larger than the Earth.
According to one study, Gliese 581d possesses a thick atmosphere made of carbon dioxide and could likely have signs of alien life.
Photo: NASA Goddard Space Flight Center | Flickr
