Radiation blasts dash hope for life on a number of exoplanets

16 Dec 2019

Illustration of exoplanet K2-33b dwarfed by its parent star. Image: NASA/JPL-Caltech

Dozens of exoplanets have been discovered with potential for hosting life, but new research shows some of these are a little too hostile.

The 21st century has seen thousands of exoplanets identified across the universe, a small number of which may host extraterrestrial life because chemical readings suggest they have large quantities of liquid water.

However, researchers publishing to Monthly Notices of the Royal Astronomical Society: Letters have thrown a spanner in the works after showing a number of these exoplanets may not be able to support life after all.

The researchers showed that if they are just a little too close to the parent star, some of these promising exoplanets may be blasted with radiation from the star, making life extremely difficult – if not impossible – to develop.

The study looked at how these radiation bursts, or flares, affect a planet’s radiation dose and whether they could disrupt its ability to host life. Researchers took into account the role of a planet’s magnetic field strength, its atmosphere in providing shielding from these bursts and the severity of the stellar flare.

‘As we continue to explore the planets of the solar system and beyond, discovering if these planets have the ability to support life continues to be of immense importance’
– DIMITRA ATRI

Particle spectra from 70 major flare-emitting events between 1956 and 2012 were used for testing, along with a model designed to simulate flare interaction with exoplanetary atmospheres.

The results showed that flares can cause radiation levels on a planet’s surface to surge and likely having the ability to seriously disrupt the process of life. It was also found that a planet’s atmospheric depth and planetary magnetic field are major factors in protecting it from flares and maintaining a substantial planetary atmosphere.

“As we continue to explore the planets of the solar system and beyond, discovering if these planets have the ability to support life continues to be of immense importance,” said Dimitra Atri of New York University Abu Dhabi.

“More progress in this area will improve our understanding of the relationship between extreme solar events, radiation dose and planetary habitability.”

This follows research from August that said exoplanets with the right ocean circulation patterns could offer a greater variety of life than what we have on Earth.

Colm Gorey was a senior journalist with Silicon Republic

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