NASA does not often crack jokes about aliens, but its recent announcement that a satellite camera had found “Martian Morse code” in the shape of sand dunes on the Red Planet’s surface inspired much mirth among space scientists.
Nathalie Cabrol, director of the Carl Sagan Center at the SETI (Search for Extraterrestrial Intelligence) Institute, which searches for alien messages, laughed out loud at the thought.
“Tell me about it,” she said sarcastically.
If only contact with aliens, if they exist, were so simple. This was just dirt shaped by wind, as NASA itself eventually conceded. Just as the wealthy American polymath astronomer Percival Lowell did not actually see canals on Mars in 1906, so too is this latest bit of Martian clickbait a figment of a rich human imagination, reflecting our desire to find patterns in chaos. But it is also revealing of a deep philosophical problem in the search for extraterrestrial intelligence, an all-or-nothing scientific gamble that is now at a crisis point.
The problem, as Cabrol describes it in a provocative new research paper, is that human scientists have only ever looked for other versions of themselves.
By scanning the heavens for the same sort of messages we ourselves sent out in the 1970s — from the Arecibo radio transmission with encoded details of arithmetic and chemistry to the engraved plaques launched on Pioneer with rudimentary sketches of a man and woman, and the Voyager golden record with music by Mozart and Chuck Berry — we have, basically, been searching blind.
NASAMartian sand dunes form a dot and dash formation that could represent Morse code. Well, not really.
“It is not a mistake. This is where we had to start,” said Cabrol, an astrobiologist and planetary geologist with a background in environmental science and the development of Mars rovers. “But we should not stay constrained or confined to that.”
“To find aliens, we must become the aliens,” she said. To that end, she described the tactical change she wants to make to the basic approach of research at SETI, which applies scientific rigour to a question — the possibility of life on other planets — that is more commonly associated with sweaty conspiracy theorists and flaky fantasists.
She described SETI’s current main strategy of looking for non-natural patterns in electromagnetic signals from other Earth-like planets as a “shot in the dark.”
“You don’t know exactly what you are looking for, or even if you found something, because you cannot recognize it,” she said.
Handout/The SETI InstituteNathalie Cabrol, director of the Carl Sagan Center at the SETI Institute: “To find aliens, we must become the aliens.”
She said the response has been enthusiastic. One criticism has come from intelligent design theorists, who believe humans were created supernaturally, not by natural physical and evolutionary processes. They conclude from this that we are probably unique in the universe.
An editorial by the Discovery Institute on Cabrol’s idea, for example, compares SETI researchers to cultish fanatics searching for ghosts, who “refuse to take non-detection as an answer … Despite continued failures, SETI is unlikely to cave anytime soon. Its motivations are too deeply grounded in evolutionary ideology. The believers think it too incredible to imagine humans as unique or exceptional in such a vast universe. To be sure, this ‘gut feeling’ extends outside evolutionary circles. But where is the evidence?”
The positive responses have generated the most excitement. For example Rene Heller, an astrophysicist at the Max Planck Institute for Solar System Research in Germany, recently of McMaster University, has proposed a strategy in line with Cabrol’s interdisciplinary thinking. His idea is that, because we often detect Earth-like planets by observing them pass in front of their own stars, we should assume aliens would find us in the same way. For SETI, that means looking for signals in the thin band of the cosmos called Earth’s Transit Zone, the area from which Earth can be seen passing in front of the Sun, which is only about one-thousandth of the entire sky.
Likewise, Seth Shostak, a senior astronomer with SETI, has proposed using telescopes to look for “biosignatures,” such as oxygen, in the atmospheres of distant Earth-like planets, by analyzing the light they reflect. On this theory, the oxygen content of Earth has been advertising the presence of life here for millions of years. Oxygen is simply a byproduct of photosynthesis, not a sign of intelligent life, but as he put it, “if other worlds can spawn lettuce or maybe just algae, there’s at least some chance that they could also grow something a little more interesting.”
Cabrol’s key point is that Earth bears the cumulative physical effects of all life that ever existed here, and so would any life-bearing alien planet. As she sees it, the only way to investigate that properly is to imagine all the other kinds of ways life might disrupt a planet and its atmosphere. And that takes more kinds of scientists than just radio astronomers and satellite technicians.
“I’m going to go back to my French background here,” Cabrol said. “We had many different Gaul villages all over the place, and the only time we beat Caesar is when they all came together … In the 15 years that I’ve been doing this, I saw how powerful synergies and bridges between disciplines are.”
Seth Shostak, SETISETI’s
current main strategy of looking for non-natural patterns in
electromagnetic signals from other Earth-like planets is described as a
“shot in the dark.”
For SETI, part of the problem is radio astronomers who do not know much about the origins of life, or astrobiologists who do not understand general relativity.
If there are messages out there, the fear is we are failing to recognize them, either because we cannot recognize them, or we are not looking in the right way.
Part of the solution is, like in brain science, major funding pushes. Earlier this year, the Russian venture capitalist Yuri Milner announced a doubling of his $100-million contribution to SETI projects.
The other part is philosophical, a return to first principles. Like the best science, the search for alien life eventually runs up against a deep philosophical question — what is life in the first place?
(OFFICIAL VIDEO ) 
