BioScience: Alien Life Could Hitchhiker to Earth and Become Invasive

In the journal BioScience there was an article about the danger threatening the space "ecosystem", reports LiveScience. Invasion biologists from McGill University in Montreal believe that a situation that often occurs on Earth could occur in space when, as species move to new conditions, they become invasive and harm local flora and fauna.

“The search for life outside our world is an exciting endeavor that could lead to important discoveries in the not too distant future”, - they write. “However, in the face of an increase in the number of space missions (including those designed to return samples to Earth), it is extremely important to reduce the risks of biological pollution in both directions”. The researchers are calling for increased interaction between astrobiologists searching for extraterrestrial life and invasion biologists studying invasive species on Earth.

The risk of interplanetary contamination is low, largely because the harsh conditions of space make it difficult for potential hitchhikers to survive outside of spacecraft. However, we must be careful.

Anthropogenic influence has already led to damage to ecosystems around the world: people brought organisms into new environments that would never have got there in natural conditions, and they began to displace native species. Island ecosystems, which develop in geographical isolation, are especially vulnerable: the wildlife in these places has not developed adaptation mechanisms to deal with invaders. “Biological invasions have often been devastating to plants and animals in these systems,” the researchers write. "Planets and moons that potentially harbor life should also be considered island systems".

As evidence of interplanetary pollution, the researchers cite the case of the Israeli spacecraft "Bereshit". In 2019, it crashed into the moon, with thousands of tardigrades on board - microscopic animals that can survive in extreme conditions, including in the vacuum of space. A study published this year in the journal Astrobiology found that tardigrades likely did not survive the accident. However, the incident itself demonstrates the potential for biological "spills".

Space agencies are aware of the potential risks of biological contamination, and there has been a policy of protecting planets since the 1960s. However, these guidelines are not binding, and the intensification of space exploration, including the growth of private companies carrying space tourists, creates new and unprecedented risks.