Statistiche

Monday, May 20, 2019

When NASA Thought Bacteria Had Survived on the Moon




After years of planning lunar missions — not to mention the centuries humans have spent wondering what other forms of life lurk outside our world — the scientists examining equipment from the moon probe Surveyor III must have been surprised when the results of a microbial test came back from the lab.

Retrieved by the crew of Apollo 12 in November 1969 after more than two years on the moon, items from the lunar lander presented the perfect opportunity to study how various objects were affected by long-term exposure to space. After all, if NASA was going to establish a permanent presence on the moon, researchers would need to know exactly how the frozen, irradiated and generally forbidding environment of space would affect material as diverse as delicate cloth and intricate wiring. Until then, Surveyor III, which wasn’t sterilized prior to its April 1967 launch, had been the only object retrieved after such a long period of time in space.
Back on Earth, one of the samples which scientists inspected, pulled from deep within the spacecraft’s camera, showed traces of Streptococcus mitis, a bacteria common to the human respiratory system. These microbes couldn’t have come from space — meaning they must’ve contaminated the probe before its launch, then spent two and a half years living on the lunar surface, using Surveyor III as their makeshift home. For Apollo 12 commander Charles “Pete” Conrad, the discovery amounted to the highlight of his trip, later commenting that it was “the most significant thing that we ever found.”


Gettyimages 576878676
The unmanned Surveyor III lunar lander, photographed by the astronauts of Apollo 12.
Source Getty Images


The discovery attracted widespread attention. John Rummel, a professor of biology at East Carolina University, points to the popular culture of the time: It was heavily influenced by a deep fascination in all things cosmic and unknown. Just think of Michael Crichton’s The Andromeda Strain, published only months before the Apollo 12 mission, which details the terror on Earth that follows an outbreak of a mysterious extraterrestrial virus. Over the years, mention of the Surveyor III discovery popped up in media as varied as press reports and late-night comedy skits, Rummel says.
There’s just one problem, Rummel believes: It was all a sham. Having spent more than a decade chasing down a hunch, he co-authored a 2011 report aimed, he says, at “setting the record straight.” After obtaining images from the inspection, he highlighted what might easily embarrass any modern researcher: Scientists scoping out the probe’s camera were working in short sleeves, and one of them even appeared to have touched a pair of pliers against his naked arm. “The only one out of 32 samples that had a positive result was taken with those pliers,” Rummel says.

If that improper handling was indeed the cause, one might ask: How could scientists have missed such a basic detail?



And that’s not even to mention how the camera was returned to Earth by the Apollo crew: effectively stuffed into a duffel bag, devoid of the sterile or air-tight environment typically afforded lunar samples. That’s why it’s entirely possible, according to NASA’s own Life Sciences Data Archive, that it was contaminated inside Apollo 12’s command or lunar modules — which, obviously, were meant to sustain human life.
If that improper handling was indeed the cause, one might ask: How could scientists have missed such a basic detail? To be fair, mission planners had many other pressing issues on their minds: Catapulting humans at thousands of miles per hour around an object 230,000 miles away, then blasting them through the atmosphere, effectively inside a careening fireball, took up plenty of attention. Contamination was indeed a concern — but the kind aimed at preventing the introduction of foreign bacteria to Earth, which explains why the first few moon-walking astronauts were quarantined for nearly three weeks upon their return.

Gettyimages 2644218
Astronaut Alan Bean with a container of lunar soil collected during Apollo 12 extravehicular activity. He wears a checklist on his left wrist and a Hasselblad camera to record his movements.
Source Getty Images




Still, some believe it’s not entirely impossible for the bacteria to have survived on the moon. They’ve argued that upon landing on the moon, the particularly hardy Streptococcus microbes entered a sort of hibernation mode that allowed them to survive the extreme environment. Not so, says Seth Shostak, a senior astronomer at the SETI Institute in Mountain View, California. “Put whatever you like in a vacuum,” he says, “and you’ll find that it doesn’t do very well.”
These days, Surveyor III’s camera is on display at Washington’s Smithsonian National Air and Space Museum. Meanwhile — and perhaps needless to say — NASA’s procedures have improved considerably. But for some, it’ll never stop them from wondering: What can survive out there?
  
 Dan Peleschuk

Source News 

CORRECTION: An earlier version of this story incorrectly implied that astronauts retrieved the entire Surveyor III probe when they had really returned with several pieces of equipment, including its camera.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.