We should be able to detect signs of life like amino acids on Saturn’s moon Enceladus without destroying them in a high-speed collision.
In 2005, NASA’s Cassini spacecraft found evidence that plumes of water ice were erupting from Enceladus, with images showing clear evidence they were coming from the moon’s south pole region. Later studies suggested these plumes originated from a subsurface ocean, located beneath an icy shell, which could host conditions right for life.
Cassini itself wasn’t able to look for life in the plumes, lacking the necessary instruments, so at the University of California, Berkeley, and his team performed experiments to see if a future mission might be able to do so. By firing ice particles into metal foil with a gas gun at speeds of up to several kilometres per second, the team simulated how a spacecraft flying through the plumes might be able to capture material.
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Their experiments showed that even at speeds of up to 3 kilometres per second, a spacecraft could capture sufficient material to be studied on board to look for evidence of life, such as amino acids or sugars. “The organic molecules survive the impact,” says Mathies.
A craft orbiting Saturn would be able to travel at speeds of less than 3 kilometres per second as it flew past Enceladus to sample the plumes. If it orbited the moon, it would be even slower – 200 metres per second – making sample capture even more efficient.
No mission to Enceladus is currently in development, however Mathies and his team hope their findings might inform the planning for one. “Enceladus presents an outstanding opportunity, because it basically presents a sample to us automatically,” he says
The Planetary Science Journal
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