Astronauts face space age risk

Astronauts who spend too long in space may age prematurely and become more prone to cancer, new research suggests.

Radiation in space can cause damage to living tissue

The findings from scientists in the US could have major implications for plans to build moon bases and send explorers to Mars.

The risks come from exposure to "space radiation" according to the researchers, who were funded by the American space agency Nasa.

They found evidence that the high energy particles which float through space can have a harmful effect on mice.

Cancer risk

In a new report, the scientists claim that the particles can damage DNA.

They found that the biggest effect was on the gut, and that is likely to lead to an increased risk of colon cancer.

The mice who were exposed to radiation also aged prematurely, with their fur turning grey.

Radiation exposure, either intentional or accidental, is inevitable during our lifetimes Dr Kamal Datta

Dr Kamal Datta, who led the study at Georgetown's Lombardi Comprehensive Cancer Centre, said: "Radiation exposure, either intentional or accidental, is inevitable during our lifetimes. But with plans for a mission to Mars, we need to understand more about the nature of radiation in space."

The kind of radiation found in space is known as high LET (linear energy transfer) radiation. It can cause concentrated damage to living tissue.

People on Earth are shielded from it by the planet's atmosphere, but in space there is nothing to stop astronauts being blasted by the particles.