Scientists and doctors have a long history of paying inadequate attention to very serious risks that are hard to quantify. Here are some examples.
- When the first atomic bomb was being developed, there were concerns that its explosion would cause an uncontrollable chain reaction that would set the Earth's atmosphere on fire. Anyone familiar with the way in which an atomic chain reaction occurs may understand why such a concern was reasonable. A nuclear chain reaction occurs in a way roughly comparable to how a fast-spreading virus spreads, with the reaction passing on very quickly between nearby units, which themselves cause the same reaction to be passed on to other nearby units, and so on and so forth. It was reasonable to fear that an atmosphere filled with oxygen molecules might allow a nuclear chain reaction to pass on endlessly from one molecule to the next. Chapter 17 of Daniel Ellsberg's book The Doomsday Machine makes quite clear that physicists still thought there was a significant chance of such a planet-killing event when the first atomic bomb was exploded in July, 1945. At one point Enrico Fermi estimated the chance at 10 percent, according to one source. Scientists basically shrugged off the risk that the whole atmosphere might burn up when the first nuclear bomb exploded, and approved the first atom bomb test. It was like playing Russian roulette with the survival of mankind.
- After nuclear weapons were invented, there were all kinds of concerns about the testing of nuclear weapons. Critics said that the tests were creating radioactivity that would increase the cancer risk for very many people. Scientists assured us incorrectly that the risks were very small. This post states that there were between 340,000 to 690,000 US deaths caused by atomic testing. The result was probably more US deaths than from the bombs dropped on Japan.
- Many people pointed out the hazards of scientific experimentation modifying the genomes of viruses and bacteria. But scientists recklessly kept up "gain of function" experiments. Three US intelligence agencies have concluded that the COVID-19 epidemic surging in early 2020 was caused by a lab leak from a laboratory doing gain-of-function research.
- A health resource web page states this: "For over two decades, the United States has experienced a crisis of substance abuse and addiction that is illustrated most starkly by the rise in deaths from drug overdoses. Since the year 2000, over 1 million people died from drug overdoses in the United States. The annual number of drug deaths exceeded 100,000 for the first time in 2021, beginning a disturbing trend that has continued in both 2022 and 2023." How did this happen? For many years, doctors not paying adequate attention to the risks of opioid medicines went about casually writing prescriptions for such drugs, acting like they were blind to the risks of overdoses and prescription drug addiction.
- The radiation hazards of CT scans were obvious from the beginning. But countless millions were encouraged to get such scans, often where there was no clear medical necessity for such a scan. Referring to CT scans in the United States, a scientific study stated, "The 93 million CT examinations performed in 62 million patients in 2023 were projected to result in approximately 103, 000 future cancers." Extrapolating, we can assume that millions of people worldwide have got cancer because of unnecessary CT scans.
Scientists have recently discussed a type of risk that few have imagined previously. It is the risk called "mirror life." To understand the idea, you have to understand the important idea of homochirality.
A protein molecule typically has hundreds of amino acids. Chemicals such as amino acids and sugars can be either left-handed or right handed. A left handed amino acid looks like a mirror image of the right-handed amino acid, and a right-handed sugar looks like the mirror image of the left-handed sugar. Homochirality is the fact that in living things essentially all amino acids are left-handed, and all sugars in DNA are right-handed. But when such things are synthesized in a laboratory, or produced in experiments simulating the early Earth, you see equal amounts of left-handed and right-handed amino acids and equal amounts of left-handed and right-handed sugars.
But what if life had arose on Mars long ago? Such life might have a type of homochirality the exact opposite of the type we see in earthly life. For Mars life it might be that all proteins used right-handed amino acids, and all sugars were left-handed. Such a theoretical form of life is called "mirror life." Recently articles have pointed out a great danger in trying to create such mirror life through laboratory experiments. If such mirror life escaped a lab, it might act like an unstoppable virus. Theoretically if mirror life were unleashed in the earthly biosphere, it might wipe out all or a large fraction of earthly life.
So there is a danger in returning samples from Mars that might contain life. Such life might be mirror life. And if such mirror life escaped the lab, it might act like some unstoppable virus. The result might be a pandemic that might make the COVID-19 pandemic look like "a walk in the park" in comparison.
The possibility I am mentioning is not some weird speculation I dreamed up myself. The possibility of a mirror life pandemic was raised recently in an article published in the Bulletin of the Atomic Scientists. The article had the title "Black swans from the Red Planet—Could NASA bring back 'mirror life' from Mars?" The subtitle read this:
NASA and the European Space Agency plan to bring samples back from Mars. Could they harbor a type of life that scientists warn could trigger mass extinctions on Earth?
Later in the article we read this: "With perhaps a 50-50 chance that any Martian life developed from a mirror biology, the return of samples from Mars has transformed from a scientific opportunity to a potential existential risk."
The possibility of a mirror life pandemic after a Mars sample return mission is another reason why such a mission should not be funded. The main reason is the very low likelihood of detecting life or traces of dead life, given that no type of amino acid has ever been detected on Mars. Amino acids are the building components of protein molecules, which (along with protein complexes) are the building components of the simplest one-celled life.
A more intelligent approach would be to send to Mars robotic instruments with whatever equipment is sufficient to detect life, if it exists. Or, simply wait until a manned expedition reaches Mars, a mission including a competent biologist with all the tools needed to detect whether life on Mars exists or ever existed.












