It’s now known that the living conditions in space can wreak havoc on the human body – but how might the human body leave its mark on the cosmos?

Plans for more rigorous missions have increased the likelihood for the eventual death of an astronaut in space, and scientists now say it’s possible that a rogue corpse could provide the spark for life on another planet.

While the conditions would have to be ‘ideal,’ a human body that manages to avoid incineration in the atmosphere and lands on a distant world could transport microbes or even act as the ‘starter-pack’ for the emergence of life.

Plans for more rigorous missions have increased the likelihood for the eventual death of an astronaut in space, and scientists now say it’s possible that a rogue corpse could provide the spark for life on another planet

HOW LIFE COULD START The successful transport microbes would be dependent on three major factors: protection of the corpse, its storage, and the corpse’s flight time. The body would have to be encased in a spacecraft for the microbes to survive passage through the atmosphere. Along with this, it would need either to be kept in above-freezing temperatures that would allow for liquid water, or freeze-dried. And, longer time spent floating in space will subject the corpse to higher amounts of cosmic radiation, limiting microbial survival. Even if all microbes are killed, scientists say the corpse could spark new life if it landed on a planet which already hosts certain fundamental molecules, like the DNA building blocks triphosphates. And, a new genesis would have a much better chance if entire ill-fated crew landed in the right environment. Advertisement

Under a certain set of circumstances, microbes carried by a human corpse might be able to survive the space environment, especially in a world like Mars, explained Louisiana State University microbial biologist Gary King in an interview with Astronomy Magazine.

The researcher, who studies microbial life in extreme environments, says these organisms are already known to live in harsh, space-like conditions.

‘We’ve pulled microbes out of permafrost, and there we’re talking about organisms surviving around one million years in suspended animation,’ King told Astronomy Magazine.

‘Especially if the trip is somewhere close, like to Mars, bacterial spores in the human body will survive for sure.

'It’s also possible that other, non-sporing bacteria could survive as well.

‘I’m thinking about microbes like Deinococcus radiodurans, which we know can survive low levels of water and high amounts of ionizing radiation.’

But, the successful transport of such microbes would be dependent on three major factors: protection of the corpse, its storage, and the corpse’s flight time.

Under a certain set of circumstances, microbes carried by a human corpse might be able to survive the space environment, especially in a world like Mars, explained Louisiana State University microbial biologist Gary King

The body would have to be encased in a spacecraft or something similar for the microbes to survive passage through the atmosphere, and in order for them to spread after landing, the craft would have to be cracked.

Along with this, it would need either to be kept in above-freezing temperatures that would allow for liquid water, or freeze-dried.

But, this second scenario could be far more likely, as the researcher notes that ‘space is kind of the ultimate freeze-dryer.’

HOW LIVING IN SPACE AFFECTS THE BODY The mass of data collected from astronauts aboard space stations has shown that the lack of gravity can wreak havoc on the body, weakening muscle and causing bones to become brittle. Now evidence suggests the spine is susceptible as well, with many crew members reporting back pain following a mission. By using MRI to scan the spines of astronauts before and after long haul space missions, researchers could see the effect reduced gravity had on their backs in more detail. On long space missions, astronauts do not experience a change in the height of their spinal discs, but the muscles supporting the spine weaken. The findings will be of importance when preparing for a mission to Mars, which could take between six weeks and 18 months, depending on whether nuclear propulsion is used. Advertisement

Microbes would also better able to survive within the solar system, as longer time spent floating in space will subject the corpse to higher amounts of cosmic radiation, Astronomy Magazine reports.

Travelling to another system, like Proxima Centauri, would severely limit survival as radiation would cause mutations within the DNA and RNA.

‘But,’ King said, ‘I won’t say impossible, if you need only one of the vast number of microbes on the human body to survive the trip.’

Travelling to another system, like Proxima Centauri, would severely limit survival as radiation would cause mutations within the DNA and RNA. Pictured above is an artist's impression of Proxima b, which orbits Proxima Centauri

Even if all microbes are killed off as the corpse plummets through space, scientists say it’s possible that it could lead to a new form of life altogether given the perfect conditions.

If the corpse landed on a planet which already hosts certain fundamental molecules, like the DNA building blocks triphosphates, it could spark life.

‘The molecules released from the decaying astronaut could potentially provide a boost to a new origin [of life] if the environmental conditions were almost perfect for life to begin, but just a few ingredients were missing or present in too low concentrations,’ Jack Szostack, a Nobel winning geneticist at Harvard Medical School, told Astronomy Magazine.