The astronomer frank drake pioneered the search for intelligent life elsewhere in the Universe. He claimed that for intelligent life, capable of communicating over inter-stellar distances, to arise on a planet, conditions must be perfect. He came up with an equation to estimate the number of civilizations in the galaxy with the means of communicating with Earth:
It might seem logical to assume that the first confirmed alien life forms will be microscopic bacteria hiding out in damp Martian soils or simple organisms swimming around the hidden seas of Europa. But a leading SETI scientist says it’s more likely we find evidence of extra-terrestrial intelligence before discovering alien bugs.
“There are two horses in the race to find life beyond Earth,” Andrew Siemion of the University of California, Berkeley, told the Association for the Advancement of Science conference in Seattle, according to News. “The first is the search for chemical signatures from planets and the second is the search for extra-terrestrial intelligence. Intelligent life has the edge, as it can be detected across the entire galaxy.”
Siemion gave a talk entitled “Hunting for Techno signatures” at the conference in the same week he announced a major data release from the Breakthrough Listen initiative, where he is principal investigator. (The data has yet to return any evidence of ETI.) Siemion explained that the search for simpler forms of life that we might intuitively assume are more abundant and therefore easier to find is actually quite limited. The problem is that technology available now and in the near future restricts us to looking at our solar system and nearby stars. “And we can never be sure that methane or similar chemicals which we detect are really produced by living things,” Siemion said. “It just comes down to statistics – basic life may be very common, but we are much less likely to find it.”
Intelligent life, on the other hand, can send evidence of its existence across the cosmos at the speed of light as radio waves, laser pulses or other forms of electromagnetic radiation. SETI scientists increasing refer to looking for these signals that could never be created by nature and other signs of alien technology as the search for technosignatures.
Now, as we race towards 2021 without seeing that detection, x is therefore becoming ever closer to zero. And 1,000 times zero equals zero. But Siemion confirmed that he is actually optimistic and he does believe in the other side of the equation, which indicates that our capacity to detect alien life will be three orders of magnitude greater in the coming decade than in the 2010s. “We’ve seen a dramatic explosion in the number of observatories, the number of scientists… that are working in this field,” he explained.
But if we do find simple life in our solar system before detecting ETI’s signals, it could point to a rather dark conjecture: that life in the universe is plentiful, but it rarely survives long enough to develop the capability to reach beyond its own world.