The caves that could hold clues to alien lifeforms
LIFEFORMS which have been living inside crystals for up to 60,000 years have been revived by Nasa, raising hopes that alien organisms could be found in extreme environments on other planets.
Penelope Bolton, the director of Nasa’s Astrobiology Institute, and her team have spent years exploring Mexico’s Naica Mine in Chihuahua looking for extremophiles – organisms that thrive in hostile conditions.
The mine, which contains caves as large as cathedrals, is filled with giant gypsum crystals that look so extraordinary that when Dr Bolton first saw a picture, she assumed it had been doctored digitally.
But more astounding was that inside the crystals, tiny bugs were discovered in a state of “geolatency” – where living organisms remain viable in geological materials for long periods of time.
“Much to my surprise we got things to grow,” said Dr Bolton. “It was laborious. We lost some of them – that’s just the game. They’ve got needs we can’t fulfil. That part of it was really like zookeeping.”
Around 100 different bugs, which were mostly bacteria, were found inside crystals, where they had been trapped for between 10,000 and 60,000 years. Ninety per cent had never been seen before.
The cave system sits above a large pocket of volcanic magma and is geothermally heated to temperatures of up to 140F (60C), which has led to astrobiologists dubbing it “hell”.
Most life could not survive there but scientists have discovered some organisms have evolved to feed on the sulphides, iron, manganese or copper oxide in the cave. “They’re really showing us what our kind of life can do in terms of manipulating materials,” said Dr Boston. “These guys are living in an environment where there’s not organic food as we understand it. They’re an example at very high temperatures of organisms making their living essentially by munching down inorganic minerals and compounds. This is maybe the deep history of our life here.”
Other caves were detected with “weird life forms” but accessing them was too dangerous.
Scientists said the discoveries raised the possibility that dangerous bugs could hitch a ride back to Earth when spacecrafts return from other planets.
Nasa has plans to bring back rock and ice samples from Europa, an icy moon of Jupiter, which is one of the best targets in the solar system for life because it has a salty ocean beneath its crust.
Dr John Rummel, from the Seti Institute in California, said it was “pretty easy” for bugs to survive space journeys as long as they are shielded from the sun’s ultraviolet radiation.
“If we bring samples back from either Europa or Mars, we will contain them until hazard testing demonstrates that there is no danger and no life, or continue the containment indefinitely while we study the material,” he said.