Scientists discovered these superflares are equivalent to 100 billion tonnes of TNT.
A devastating event may have occurred to the most Earth-like exoplanet that we know to exist. Kepler-438b has been blasted by superflares that are equivalent to 100 billion tonnes of TNT each. Scientists detected these solar flares using photometry — a technique that measures the intensity of an object's electromagnetic radiation.
Kepler-438b is 430 light years away and has the highest recorded Earth Similarity Index. It is similar to Earth in both size and temperature, but it is closer to its Red Dwarf than Earth is to our sun. Therein lies the problem.
Radiation from the planet’s sun, Kepler-438, has more than likely stripped the planet of its atmosphere, leaving it uninhabitable with no chance for life. Chloe Pugh, from the University of Warwick’s Centre for Fusion, Space and Astrophysics said, “The presence of an atmosphere is essential for the development of life. [...] 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.”
Earth’s sun has superflares, although they occur roughly every 350 years, but they do not strip away our atmosphere. So why would Kepler’s atmosphere be blasted away? It turns out it is not the superflares themselves that will remove the atmosphere, but the coronal mass ejection (CME) associated with the intense flares. CMEs are huge explosions of plasma and magnetic field that are capable of stripping away a planet’s atmosphere. Unfortunately for Kepler-438b, superflares from its sun occur every few hundred days and are ten times more powerful than any ever recorded by Earth’s sun.
But not all hope is lost for this planet. According to the lead researcher, Dr. David Armstrong of the University of Warwick’s Astrophysics Group, “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.”
Kepler-438b is not the only exoplanet that scientists think could be potentially habitable. There are currently 31 planets that may be capable of sustaining life outside of our solar system listed on the Habitable Exoplanet Catalogue. So don’t fret, there is still a chance of finding life on other planets.