There are several rocky, Earth-like planets orbiting nearby stars, such as out closest solar neighbour – Proxima Centauri. A rocky planet called Proxima b, which is 4.24 light years away from us, orbits Proxima Centauri, but researchers had argued that it is bombarded by too much radiation from its host star. Scientists believe the levels of radiation hitting Proxima b are 250 times higher than the doses we receive, meaning it is probably too high for life to evolve.
But a new argument put forward suggests there is strong evidence that life can begin to evolve in such extreme conditions, and that evidence is us.
Some four billion years ago, life on Earth began to emerge and at the same time the planet was a hot mess, receiving more radiation than Proxima b does today.
This means there is every chance that life is emerging on Proxima b, and other similar nearby rocky exoplanets – planets outside of our solar system – such as TRAPPIST-1e, Ross-128b and LHS-1140b.
All four of the planets were compared to Earth now and our planet in its past, and scientists discovered the levels of radiation the exoplanets receive is much lower than what Earth was bombarded with 3.9 billion years ago.