Earth-Like Kepler Planet Not Suitable For Life?
A worthy contender to the title 'Earth-like' may not be as sweet as home, a new study finds.
The Washington Post reports the study on Kepler-438b, a planet 12 percent bigger than Earth and said to be at the right distance from its parent star to hold water. After its discovery was announced in January, the planet was considered one of the most Earth-like planets known given that it is believed to be rocky and within the habitable zone of its red dwarf parent star Kepler 438.
In the new study published in the Monthly Notices of the Royal Astronomical Society, researchers said that the planet may have been rendered uninhabitable due to radiation from its parent star's flares.
"Unlike the Earth's relatively quiet sun, Kepler-438 emits strong flares every few hundred days, each one stronger than the most powerful recorded flare on the Sun. It is likely that these flares are associated with coronal mass ejections, which could have serious damaging effects on the habitability of the planet," David Armstrong at the University of Warwick said in a press release.
Earth's magnetic field shields it from solar flares and the associated radiation, protecting the life-sustaining atmosphere. Without a magnetic field, Earth would have met Mars' fate.
Given that the planet is 470 light-years away, researchers do not know yet if Kepler 438b has a protective magnetic field. Even if it does, the planet could have lost its atmosphere to strong coronal mass ejections from its parent star.