We are close to bringing large-scale samples back from Mars. For some, this is a serious mistake

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In The War of the Worlds, the book by HG Wells, the Earth was suffering from a Martian invasion. The aliens overwhelmed humans with their technology but ended up succumbing to earthling bacteria. An oddly analogous situation worries some experts. In it are the Martian bacteria that attack the Earth. Today it is as much a science fiction scenario as Wells’s work, but planetary protection is a serious matter that from time to time returns to the public discussion.

Our plans to study Mars.
The space agencies of Europe (ESA) and the United States (NASA) on the one hand, and China (CNSA) on the other, have finalized their plans for the missions that should bring samples from Mars at the beginning of the next decade. The US-Euro plan is already somewhat underway, with the Perseverance probe having already collected and stored several samples.

These plans also have a bureaucratic side. Just two years ago, the United States updated its protocols for planetary protection, introducing new government agencies to assist NASA in the task. These protocols prevent the movement of probes and samples between the Earth and other bodies in the Solar System from causing biological contamination in one direction or another.

This new framework comes from the protocols established during the first space race in the late 1950s. The new space race is going to be very different from the previous one, so renewing the planetary protection policy was a necessity, as the accident of the Beresheet probe on the Moon in 2019.

Five categories.
Space missions can be classified into five categories based on the risk of contamination, with the first categories referring to low risks and the next two referring to missions destined for areas that could be inhabited (such as Mars). These missions must be decontaminated from terrestrial biological traces to avoid contamination in the Earth-Mars direction. It would be terrible for space exploration to bring life to the red planet before knowing if indigenous life exists.

The fifth category refers to contamination in the reverse direction, between an extraterrestrial body, Mars for example, and Earth. It is the most restrictive level. That Martian microorganisms reached Earth and contaminated it for sure would not cause catastrophic problemsbut that does not mean that they could not settle on our planet and alter our biosphere.

Perseverance and NASA's plan to collect samples from Mars, analyze them and send them to Earth

NASA consultation.
There are those who believe, however, that this risk is unacceptable. NASA opened a consultation on the subject and, after randomly consulting a few of the 170 opinions received, it can be said that the plan generates between skepticism and alarm. “I can’t even bring fruit from my own country, Mexico (…) No, I’m not happy with this,” said one participant. “It doesn’t sound like a good idea. It could be dangerous too” indicated an anonymous.

Not everything was frontal opposition “my only concern is that this mission may be too late if SpaceX reaches Mars in this decade as intended.” Some simply asked for caution and several are inclined to study the samples outside the planet, in a future lunar base, for example. a recent article in Scientific American found the same trend.

Advantages and disadvantages of bringing samples.
The truth is that if the trip of the samples has been raised, it is because the Martian rocks have a lot to tell us and we cannot read all this message from here. Until today ten missions have managed to land platforms and vehicles on the red planet. This includes Curiosity and Perseverance, two one-ton mobile laboratories with a multitude of instruments to analyze land, air and what might be left of the sea.

Despite this, there are many tests that they cannot perform, for which it is necessary to bring samples to be analyzed in a laboratory. The samples could give us some invaluable clues about the origin of life on our own planet, about how our system was formed, and about other topics that we might come across unexpectedly.

The risk of reverse contamination.
There is another important issue in favor, and it is the one pointed out by the last commenter. Reverse contamination is possible, and the efforts of some public and private agents to reach Mars will make it inevitable.

The search for life on the red planet must necessarily precede the arrival of human beings in this place. Decontaminating a person is impossible, when people arrive on Mars their biome will arrive with them, if you have to look for life you have to do it before.

Justified skepticism.
Not all are points in favor. The trip back to Earth is dangerous and the containers that bring the samples could be damaged, causing leaks that release biological organisms on Earth. It is likely that the (hypothetical) Martian microorganisms could not survive and reproduce on Earth, but it is far from impossible. As with the debate over radio broadcasting, there are many, including in the scientific community, who are reluctant to take risks, seeing them as unjustified or excessive.

It must be taken into account, yes, that the alternatives are not simple. For example, the possibility of analyzing the samples in a controlled environment outside the Earth (on the International Space Station or on a lunar station) would only introduce an intermediate step to contamination, since the astronauts returning from the base could bring with them biological contamination.

Perhaps a clearer alternative is simply to wait. Maybe in the future we’ll be able to better analyze samples from Earth to make sure before we bring them back. We could also in theory prepare safer trips. In any case, this would imply delaying sine die plans to travel to Mars or give up the search for its native life until we have tools to distinguish terrestrial and Martian life. It would be like turning Mars into a real protected nature reserve.

It is not certain that these latest ideas will be to everyone’s liking. Ultimately cross-contamination between Mars and Earth is going to be inevitable if colonization plans go ahead. And the truth is that we should not go so far to see that the arrival of Martian samples is going to happen. NASA/ESA and CNSA plans continue to advance and, although the deadlines are not met, it seems that a multinational agreement to put a stop to the space race is not on the table.

International diplomacy is not going through its best moment and at least the space race so far has given us better results than the arms race. Only time will tell if the germs are on our side this time as in Wells’s novel.

Image | POT

In The War of the Worlds, the book by HG Wells, the Earth was suffering from a Martian invasion. The…

In The War of the Worlds, the book by HG Wells, the Earth was suffering from a Martian invasion. The…

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