An unmanned lunar probe – the third of the Surveyor
series – which soft-landed on the Moon
near Oceanus Procellarum on April 20, 1967. Two and a half years later,
on November 20, 1969, Apollo 12 astronauts
Pete Conrad and Alan Bean
recovered the camera from Surveyor 3 and brought it back to Earth.
When NASA scientists examined the camera they found that the polyurethane
foam insulation covering its circuit boards contained 50 to 100 viable specimens
of Streptococcus mitis, a harmless bacterium
commonly found in the human nose, mouth, and throat. Since the camera had
been returned under strict sterile conditions, it is evident that the microbes
must have been on the probe since it departed the Earth and had survived
31 months in the absence of air or water while being subjected to huge monthly
temperature variations and bombardment by hard ultraviolet radiation from
the Sun. Conrad later commented: "I always thought the most significant
thing that we ever found on the whole ... Moon was that little bacteria
who came back and living and nobody ever said [expletive] about it."
This is one of a number of remarkable examples of the extreme survivability
of bacteria and bacterial spores, which
adds weight to the notion that microorganisms might be able to adapt to
conditions on worlds seemingly much less hospitable than those on Earth.
AND SPACE PROBES