Scientists from the European Space Agency (ESA) said that tardigrades can survive exposure to the vacuum and radiation of open space [1].
This discovery provides critical insight into the limits of life in extreme environments. By understanding how these extremophiles endure such conditions, researchers can better assess the potential for life to travel between planets or persist in the harsh voids of the universe.
In September 2007, researchers launched approximately 3,000 tardigrades into low Earth orbit [1]. The microscopic animals were carried aboard the ESA Foton-M3 spacecraft, where they were exposed to the vacuum of space and ionizing radiation for 12 days [1].
Upon their return to Earth, the tardigrades were rehydrated. The researchers said that most of the animals survived the ordeal and were able to breed [1]. The study highlights the unique biological resilience of these creatures, which can enter a dormant state to protect their internal structures from extreme stress.
While the Foton-M3 experiment provided confirmed data on survival in orbit, other claims regarding tardigrades in deep space remain debated. Some reports suggest that these extremophiles may have survived the crash of Israel’s lunar spacecraft, Beresheet, which would imply they could persist on the Moon [2]. However, other sources said that there is no verified evidence that tardigrades are currently alive on the lunar surface [1].
The ESA experiment remains the primary confirmed instance of tardigrades surviving direct exposure to the space environment before returning to Earth for observation [1].
“Approximately 3,000 tardigrades were sent into space, exposed to vacuum and radiation for 12 days”
The ability of tardigrades to survive the vacuum of space and maintain reproductive viability suggests that biological life is far more resilient than previously thought. This supports the theory of panspermia — the idea that life could be transported across the galaxy via meteorites — and informs the search for microbial life on other planetary bodies.
