One of the most unusual stories of the U.S. lunar landing program of the 1960s involved the Surveyor III camera that journeyed to the Moon on April 20, 1967, and sat exposed on the lunar surface for 31 months before the Apollo 12 astronauts retrieved it in December 1969. A total of five Surveyor spacecraft conducted a series of soft touch-downs on the Moon in 1966 and 1967 to provide data about its surface and possible atmosphere in preparation for human landings.
They returned over 88,000 high resolution photographs and invaluable detailed data on the nature of the lunar surface. Bringing parts of Surveyor III back from the Moon presented a rare opportunity to analyze the long-term effects of spaceflight on human materials. They did not realize at the time that it also presented knowledge about the ability of some forms of life to survive beyond this planet.
Humans, of course, cannot survive more than a few seconds while exposed to the vacuum of space. The realm has long been understood as one of the most extreme environments in which humans might ever have to operate and perhaps even colonize. Exposure to it results in nearly immediate death. The need to sustain life and productive human functions in spaceflight has presented many unique challenges to medicine and life-support technology from the dawn of the space age more than fifty years ago. Without the development of these capabilities there would have been no human exploration of space. Humans are well adapted for survival at sea level in temperate latitudes on Earth, but movement elsewhere requires considerable artificial assistance to preserve life.
Apparently, not so some extremophiles from this planet. During the Apollo 12 mission, astronauts Pete Conrad and Alan Bean piloted their Lunar Module to within approximately 160 meters of Surveyor III, walked over to it, and retrieved several pieces from the spacecraft, including its television camera and some associated electrical cables, the sample scoop, and two pieces of generic aluminum tubing. In examining the camera upon its return to Earth, scientists saw evidence of micrometeoroid bombardment. But, too, they found terrestrial bacteria—Streptococcus mitis—apparently surviving for two and a half years in the vacuum of space.
As only one of 33 samples from various parts of the spacecraft harbored the bacteria, the question arose as to whether it predated Apollo 12’s visit or resulted from accidental contamination following return from the Moon. Even so, some scientists at the time concluded that “the bacterium was deposited in the camera before launch.”
This was amazing to non-scientist Pete Conrad, the astronaut who commanded the Apollo 12 mission. He recalled in 1991, “I always thought the most significant thing that we ever found on the whole goddamn Moon was that little bacteria who came back and lived and nobody ever said shit about it.” But such a possibility was anticipated and scientists did not rigorously sterilize the Surveyors so they might learn if a microbial form of life could survive the harsh environment of space.
A planning document stated: “The precautions against the contamination of the Moon, once strict, have now been relaxed in view of our developing knowledge of the inhospitable environment for terrestrial life that exists on the lunar surface and the belief that landed contamination, if it survives, will remain localized. For these reasons, lunar landing spacecraft may have on board a low level of microbial life, they must be decontaminated but not sterile.”
There were also skeptics who dismissed the presence of the Surveyor microbial discovery as a laboratory error. Perhaps a technician inadvertently placed one of the tools used to scrape samples off the camera inadvertently on a non-sterile bench, and then reused it without re-sterilization. Dr. Leonard Jaffe, project scientist for Surveyor, stated this possibility best: “It is, therefore, quite possible that the microorganisms were transferred to the camera after its return to Earth, and that they had never been to the Moon.”
Even so, the possibility of life surviving in space gained greater credence in the 1990s, as scientists discovered robust forms of microbial life in “extreme” places on Earth. They found microbes adapted to life in the superheated water of deep-sea vents, pools of acid, and even deep within the crust of the Earth. As scientist Leslie Orgel commented in 2000, “You could take E. coli and rapidly cool it to 10° K and leave it for 10 billion years and then put it back in glucose, and I suspect you would have 99 percent survival.”
With this understanding, finding such life on other bodies with their extreme environments in our solar system now seem at least a possibility. The idea that microbial life on Earth hitchhiked to the Moon on Surveyor III and survived dormant until returned by the Apollo 12 crew remains an intriguing possibility—one with far-reaching ramifications—although the idea has largely been rejected at present. Questions abound about the possibility of extremophile life beyond Earth. As Cornell University scientist Bill Nye commented, there is “compelling evidence for astrobiologists that the environmental limits for living things are set pretty far apart.”