Prediction: NASA Will Not Find Life on Mars
The Perseverance rover landed today. As usual, the search for life is a priority for the mission.
Our prediction that no life will be found on Mars is based on history, probability, the harshness of the Mars environment and the complexity of a minimal cell. We should qualify the prediction by stipulating that if any sign of life is found, it will turn out to be remnants of Earth life that somehow got transported to Mars, perhaps by a glancing meteorite.
We can also add another prediction: a null finding will not stop NASA from looking for life on Mars. It’s impossible to prove a universal negative, for one thing. And NASA knows that the L word life is a sexy term to maintain public interest in Mars missions. NASA will keep at it even if a sample return mission brings back a sterile sample of Martian soil, because even then they could claim they looked in the wrong place.
The Perseverance Mission
The landing broadcast will be live-streamed at 2:15 p.m. EST on Live Science. When these landings work, the Earth-Martians get pretty excited. It’s fun to watch all all the emotion. A celebration is not guaranteed, of course; a multitude of intelligently-designed mechanisms have to work just right. The mission is irreducibly complex. Watch NASA’s stunning landing sequence animation to see why; if any component fails, the whole mission will fail.
If all goes well, the Perseverance rover will be exploring Jezero Crater, a location that interests scientists because it looks like water flowed into it and out of it (CBS News). The crater is dry now, but supposedly if life ever existed in the waters of the crater it would have left biosignatures scattered in the sediments. A lesson from history is in order. When the Spirit rover landed in Gusev crater in 2004, scientists had targeted that crater because they believed it had been filled with water-laid sediments, too. It turned out to be lifeless dry lava, making for a somewhat boring tour for the rover.
At The Conversation, Samantha Rolfe discusses “how to prove whether there’s life on the red planet.” The Perseverance rover is the first rover to specifically look for signs of life.
If the landing is successful, this will be the first mission in decades to actively search for direct evidence of life on Mars. This life – if it exists – will most likely take the form of extinct microbes.
The last mission that specifically looked for life, Viking in 1976, came up negative or (to some) with ambiguous results. Rolfe is excited about the subsequent discovery of methane on Mars, which has not been explained geologically to everyone’s satisfaction. The rover carries several instruments to look for life, which she describes briefly.
There are many molecules that are only made by terrestrial biology, such as isoprene or DNA. So finding something like those would allow us to move toward the conclusion that life exists or existed on Mars. If Perseverance does find such molecules, we will have the harder job of proving it was native to Mars and not a microbial hitchhiker from Earth. To help us work that out, the rover will first run “control experiments” with no sample. If the molecules are there in these experiments, they are likely to be terrestrial contamination on the rover itself.
She doesn’t mention that DNA would likely degrade quickly in the Martian environment. Perseverance will collect soil samples in caches that might be retrieved by another mission later in the decade and returned to Earth for analysis.
Rolfe offers an escape hatch if nothing is found:
All of this depends on our very narrow understanding of what life is. We only know about one kind of life – the terrestrial kind. Our experiments are searching for life within our current knowledge. It is always possible that life beyond our current understanding exists, perhaps silicon-based rather than carbon-based. Perseverance isn’t likely to detect such life even if it’s thriving on Mars.
The mission would certainly be oblivious to disembodied life forms like angels or demons, which might be very much alive but undetectable by scientific means – unless, that is, they had the power to move matter in ways that could only be explained by purposeful activity of a mind. Speaking of that, if Perseverance ran into another rover from an unknown country or an alien world, would it be able to infer intelligent design?
The mission carries another device, a demonstration helicopter named Ingenuity. If it works, it could allow future missions to “hop” over larger areas than a rover can drive. The thin atmosphere of Mars, however (with about 1% of Earth’s atmospheric density), limits the weight that a drone or helicopter can carry and the height it can fly.
Update: The craft landed successfully. After system checkouts complete over the next few days, watch for science results to start coming in.
Prepare for more excuses when life is not found on Mars. Watch, also, for the optimistic claims that we should keep looking. How long can the public take it?
CEH is all for investigating the unknown. Ground truth has been very friendly to creationists, even to young-earth creationists. Images and data are far better than speculation without evidence. Best wishes to the team for a good landing and successful data collection.
We again offer our better way to arouse public interest in Mars missions. Instead of titillating people with empty promises about alien life that are never fulfilled, why not make this the motivation: “Exploring other worlds helps us appreciate just how magnificently designed the Earth is for life.”