Planets hosted by stars with low metallicity ‘may be more suitable for life’
Low levels of ultraviolet radiation are known to lead to low planetary ozone levels, and therefore less UV protection.
Your support helps us to tell the story
From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.
At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.
The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.
Your support makes all the difference.Planets in the habitable zones of stars that do not have a lot of metals in their atmosphere may be the best targets for the search for life, research suggests.
High levels of ultraviolet (UV) radiation may cause damage to the DNA in life forms.
On Earth, oxygen in the atmosphere and the ozone protect the planet from harmful UV levels from the sun.
However, the amount of UV radiation emitted varies from star to star.
Our findings imply that planets hosted by stars with low metallicity are the best targets to search for complex life on land
Low levels of UV radiation are known to lead to low planetary ozone levels, and therefore less UV protection.
Writing in Nature Communications, the researchers said: “During the evolution of the universe, newly formed stars have progressively become more metal rich, exposing organisms to increasingly intense ultraviolet radiation.
“Our findings imply that planets hosted by stars with low metallicity are the best targets to search for complex life on land.”
However, the influence of stellar metallicity – the abundance of elements heavier than hydrogen and helium in a star – on UV protection and whether or not a planet is habitable is unclear.
Anna Shapiro, from the Max Planck Institute for Solar System Research in Germany, and colleagues modelled the atmospheres of hypothetical Earth-like planets hosted by stars with a range of metallicities.
They found that the planets around metal-poor stars would have more UV shielding, which may have implications for potential life.
While metal-rich stars emit substantially less UV radiation than metal-poor stars, the surfaces of their associated planets are exposed to more intense UV radiation.
According to the researchers, planets orbiting metal-rich stars are less suitable for life despite receiving relatively less UV radiation.