Life on 'Earth 2.0' may be wiped out by SUPER FLARES: Killer electrons from Proxima b's star could cause mass extinctions

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Earlier this year, the discovery of a habitable planet orbiting Earth’s closest stellar neighbour raised hopes that we may find alien life.

But astronomers have claimed that this 'Earth 2.0', called Proxima b, may be blasted with killer electrons from its parent star.

They claim that super flares from Proxima Centauri could bathe the alien world in ‘extinction-level’ radiation, which would wipe out life.

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Astronomers have claimed that Proxima b may be blasted with intense radiation from its parent star, which could cause regular extinction events on the rocky world. Pictured is an artist's impression of its surface

Proxima b was discovered by scientists earlier this year, when they found a rocky world orbiting the nearest star outside of the solar system – Proxima Centauri, just 4.22 light years from the sun.

Due to its position, they believe it lies in the habitable zone of the star, where conditions could potentially be right for supporting life.

But despite being in the right place for life, scientists have said that the planet’s magnetic field could be the deciding factor.

As the planet orbits so close to its dim parent star – less than the distance between Mercury and the sun – any solar flares could have a huge impact on the planet’s surface.

Proxima b was discovered by scientists earlier this year, when they found a rocky world orbiting the nearest star outside of the solar system – Proxima Centauri, just 4.22 light years from the sun (illustrated)

Dimitra Atri, an astrobiologist at the Blue Marble Institute of Space Science, believes that there is fine balance between radiation from the flare and the strength of the planet’s magnetic field.

If the field is strong enough, it can bat away the energy, just like Earth’s atmosphere deflects solar wind from the sun.

But if the magnetic field is weak, then much of this radiation would reach the surface, potentially shredding bonds between molecule and making it extremely hostile to life as we know it.

Dr Atri ran simulations of flares emitted from stars and the impact this is likely to have on their orbiting exoplanets.

Writing in a paper published in Monthly Notices of the Royal Society of Astronomy in September, Dr Atri said that while the radiation from large flares might not be enough to rid worlds like Proxima b of life completely, they could regularly stamp it out.

He explained: ‘It can be concluded that for close-in exoplanets with sizeable atmospheres and magnetospheres, the radiation dose contributed by stellar superflares may not be high enough to sterilize a planet (for life as we know it) but can result in frequent extinction level events.’

Proxima b is only 4.6 million miles (7.5 million km) from the star, 5 per cent of the distance between the Earth and the sun, and takes just 11.2 days to complete one orbit. It is around 1.3 times as massive as Earth.

PROXIMA CENTAURI'S SUN-LIKE CYCLES

After observing Proxima Centauri for more than 22 years, astronomers have found that the star experiences regular cycles of starspot activity. 

A team at the Harvard-Smithsonian Center for Astrophysics found that the star experiences regular cycles of starspot activity.

Similar to the sun, the starspots on the red dwarf are the result of magnetic fields interrupting the flow of plasma, resulting in cooler patches.

Its 7-year cycle generates huge spots which cover a fifth of the planet at the peak of the cycle, which would generate huge stellar winds.

Its unclear how these winds would affect Proxima b, the recently discovered Earth-like world orbiting the star.

But spikes in the intensity of charged particles fired out from the star could potentially strip away atmospheres, leaving planets as lifeless rocks.

Astronomers have found that one of the closest stars to Earth, Proxima Centauri, experiences regular cycles of starspot activity, like the sun. Scientists recently discovered an alien world, Proxima b, orbiting the red dwarf star which could hold oceans and even conditions for life

But because Proxima Centauri is a dim red dwarf star radiating much less heat than the sun, it still occupies the 'habitable zone' where temperatures are mild enough to permit liquid surface water.

The temperature on the surface of the planet could be between -90° and 30° Celsius (-130 and 86 Fahrenheit).

On the other hand, the planet is blasted by powerful ultraviolet rays and X-rays from the star. Any life that evolved on its surface would have to be hardened against the radiation.

Speaking to Space.com, Dr Altri said: ‘One important aspect of this work is highlighting the critical importance of having a significant planetary magnetic field and good atmospheric shielding.

‘With these two factors, even the most extreme stellar flares will not have much impact on a primitive biosphere.’

But even if the small rocky world was frequently doused in ‘extinction level’ radiation, it could be a possible that any life had become adapted to the conditions, even flourishing under such otherwise hostile conditions. 

A recent study from Dr Atri and colleagues suggests life on other planets might survive on the energy provided by cosmic radiation.

They focused on an Earth-bound life form as an example - the rod-shaped bacterium called Desulforudis audaxviator which lives 1.8 miles (2.8km) underground, where there is no light, carbon or oxygen.

This strange bug gets its energy from the radioactive uranium found in the mine, and could survive in similarly extreme conditions.