Planet Like Earth Is Next to Violent, Radiating Star
It turns out that the planet most like Earth may be considerably damaged already.
New research from the University of Warwick and others indicates that Kepler-438b probably has had its atmosphere stripped away by radiation from a violent Red Dwarf star, Kepler-438, according to a release.
That star is really busy sending up superflares every few hundred days--those are explosions of up to 10 times the energy of the flares that regularly occur from our sun, for instance, and are equal to about 100 billion megatons of TNT (take that, Wile E. Coyote of the exoplanets), the release confirmed.
Even so, the superflares alone probably don't significantly affect the atmosphere of the Earth-like planet. But they're accompanied by another phenomenon: coronal mass ejection (CME), which has the ability to shake off the atmosphere and make the planet uninhabitable, noted a statement.
The problem in this case is that Kepler-438b, while Earth-like, is nearer to the Red Dwarf star than Earth is to our Sun. Also, the planet may or may not be shielded a bit. "If the planet, Kepler-438b, has a magnetic field like the Earth, it may be shielded from some of the effects. However, if it does not, or the flares are strong enough, it could have lost its atmosphere, be irradiated by extra dangerous radiation and be a much harsher place for life to exist," Dr. David Armstrong of the University of Warwick, said in the statement.
So, what is a CME? "Coronal mass ejections are where a huge amount of plasma is hurled outwards from the Sun, and there is no reason why they should not occur on other active stars as well. The likelihood of a coronal mass ejection occurring increases with the occurrence of powerful flares, and 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. With little atmosphere, the planet would also be subject to harsh UV and X-ray radiation from the superflares, along with charged particle radiation, all of which are damaging to life," Chloe Pugh, of the University of Warwick, said in the release.
The researchers recently published their findings in the journal Monthly Notices of the Royal Astronomical Society.
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