Originally Posted by
Bobunf
I don’t believe this "slip up" is a big deal for four reasons:
1. The cleaning processes before the “final ultra-cleanliness step” may already have eliminated any life on these drill bits that would have been eliminated by the that final step.
2. If there were any life still existing on the drill bits, it may be destroyed in the voyage between the Earth and Moon, by vacuum, cold, heat, radiation, lack of nutrients or other causes over the next nine months at least to the extent that the “final ultra-cleanliness step” would have accomplished.
3. Spacecraft may already have brought Earth life to Mars at least to the extent that contamination would have been avoided by the “final ultra-cleanliness step.”
In 1962 the Soviet Union’s Mars 1 lost communication before reaching Mars. A crash on Mars was possible. It was not subject to any planetary protection procedures.
In 1964 NASA’s Mariner 3 lost communication before reaching Mars. A crash on Mars was possible. It was not subject to any planetary protection procedures.
Also in 1964 the Soviet Union’s Zond 2 lost communication before reaching Mars. A crash on Mars was possible. It was not subject to any planetary protection procedures.
These missions were all before the 1967 treaty concerning “Activities of States in the Exploration and Use of Outer Space.”
In 1971 NASA’s Mariner 9 was put into orbit around Mars. It was not subject to any planetary protection procedures. Will its orbit decay to the point that it crashes on Mars before we have found evidence of life of any kind on Mars?
Also in 1971 the Soviet Union’s Mars 2 was launched to Mars. We do know that it, in fact, did crash on Mars. Mars 2 also contained on orbiter. Will its orbit decay to the point that it crashes on Mars before we have found evidence of life of any kind on Mars? The extent of planetary protection measures, if any, for these two vehicles is unknown.
And again in 1971, Mars 3, another Soviet mission, achieved mankind’s first successful landing on Mars (carrying a tethered rover). Mars 3 also contained an orbiter, which may have crashed on Mars. The extent of planetary protection measures, if any, for these two vehicles is unknown.
In 1973 the Soviet Union’s Mars 5 achieved Mars orbit. Will its orbit decay to the point that it crashes on Mars before we have found evidence of life of any kind on Mars? The extent of planetary protection measures, if any, is unknown.
Also in 1973 the Soviet Union’s Mars 6 did crash on Mars. The craft did provide the first direct scientific measurements of the Martian atmosphere as it descended. The extent of planetary protection measures, if any, is unknown.
In 1975 NASA landed two spacecraft on Mars, Viking 1 and 2. They were subject to the equivalent of category 4 Planetary Protection Measues.
In 1988 the Soviet Union launched Phobos 1 and 2. Both missions were lost and both orbits will decay and the spacecraft will crash on Mars within 50 million years, perhaps sooner. I don’t know what Planetary Protection Measures were used, if any.
In 1992 NASA Mars Observer (an orbiter) was launched. Contact was lost in 1993, and the craft may have eventually crashed on Mars. It used Category 3 Planetary Protection Measures.
In 1997 NASA’s Mars Pathfinder landed on Mars. It used Category 4 Planetary Protection Measures.
Also in 1997 NASA’s Global Surveyor arrived at Mars. Global Surveyor achieved Mars orbit by aero-braking in the atmosphere of Mars. It was planned to raise it’s orbit near end of mission in order to prevent any near term orbit decay and crash on Mars, but the craft failed before this was accomplished. It used Category 4 Planetary Protection Measures.
In 1998 Mars Climate Orbiter crashed on Mars. It used Category 3 Planetary Protection Measures.
In 1999 NASA’s Mars Polar Lander was lost on entering the Martian atmosphere. It used Category 4 Planetary Protection Measures.
In 2002 NASA’s Odyssey spacecraft used aero-braking to enter Mars orbit. It used Category 3 Planetary Protection Measures.
In 2003 the European Space Agency’s Beagle crashed on Mars. It used Category 4 Planetary Protection Measures.
Also in 2003 NASA’s Mars Exploration Rover spacecraft – Spirit and Opportunity – landed on Mars. They used Category 4 Planetary Protection Measures.
In 2006 NASA’s Mars Reconnaissance Orbiter using aero-braking entered Mars orbit. It used Category 3 Planetary Protection Measures.
In 2008 NASA’s Phoenix spacecraft landed on Mars. It used Category 4 Planetary Protection Measures.
I think that's about 25 spacecraft that have landed, crashed, may have crashed, may crash someday on Mars. or that used aero-braking in the Martian atmosphere. I may have forgotten some. These craft were launched over nearly a 50 year period, by three different national entities, with changing planetary protection criteria.
I would find it hard to believe that there have not already been a number of instances in which spacecraft have interacted with Mars without Category 4 Planetary Protection Measures. Even in those cases where such measures were taken (six I believe), may there not have been other slip-ups, known and unknown, announced and unannounced?
4. In the (in my opinion) very unlikely event that biological contamination of Mars has not occurred from spacecraft interacting with Mars, I find it even harder to imagine that sometime in the last four billion years something didn’t happen to transport Earthly life to Mars, whether from impacts or some other process.
As many as 100 Martian meteorites have been found on Earth. Obviously only the tiniest fraction of such meteorites have been found. Only about 1% of all meteorites currently landing on Earth are found. Meteorites that landed long ago are found at much lower rates. I think that suggests there must have been many millions of Martian meteorites that have impacted Earth.
The process may not be as robust going the other way, but it must surely have happened in the thousands at least. The study “Dynamics of escaping Earth ejecta and their collision probability with different Solar System bodies” by M. Reyes-Ruiz. Et al suggests that for certain types of impacts on Earth, the probability of ejecta landing on Mars is about 50% of that of landing on the Moon.
So. Don’t worry. Enjoy life.
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