The answer to why we seem to be alone in the universe might be underneath your feet, scientists say

Plate tectonics might be key to life on Earth – and why we have not found it anywhere else

The reason we seem to be alone in the universe might be right beneath your feet, scientists have suggested.

For years, scientists have been perplexed by the fact that we have not found any other kind of alien civilisation.

That is despite the fact that the Drake equation suggests there should be many civilisations near enough and capable enough to get in contact with us. The equation – originally posited by Frank Drake – attempts to estimate the chances of coming into contact with intelligent life, and suggests that the chance of that should be high.

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But the new study suggests that it might have misled us by missing one key part about the emergence of intelligent life. Our Earth might be relatively rare in having the oceans, continents and long-term plate tectonics that are under our feet – and which might be essential for leading to the development of “active, communicative civilizations”, or ACCs, of the kind we are and look for elsewhere in the universe.

The Drake equation takes a series of factors that could help define the likelihood of life elsewhere in the universe. Each is in turn thought to be a pre-requisite for life.

It starts with looking at the number of stars that are formed each year, then how many of those have planetary systems, how many of those planets have an environment that could be suitable for life, how many of those see life actually appear, how often that life then becomes intelligence life, and how many of those are able to make a technology that would alert others to their existence, along with how long that all takes.

It is impossible to assign precise values to any of those variables. But researchers who have estimated have found that it suggests that life should be widespread throughout the universe, ready for us to make contact with.

We have failed to do so, however. That failure has led to the discussion of the “Fermi paradox”, named after Enrico Fermi, who puzzled over why we had failed to find life anywhere else at all.

In the new study, however, scientists suggest that we may have missed an important part of one of those variables. And that might explain why we are alone.

For a long time, researchers have believed that the chance that life on a planet would go on to become intelligence life was almost 100 per cent. But researchers suggest that it could be much lower, since it may depend on plate tectonics.

On Earth, plate tectonics suggests that the Earth’s crust and upper mantle are broken into pieces, which slowly move around and lead to dramatic natural disasters on our planet. But that is rare: Earth is the only planet in our solar system to have plate tectonics, even though there are three other rocky objects in Venus, Mars and Io, Jupiter’s moon.

Having plate tectonics means that mountains, volcanoes and oceans are formed; they also contribute to weathering, which releases nutrients into the ocean; and by making and destroying habitats, any life on the planet is required to evolve and adapt. That process might be necessary to lead to the intelligent life that we have on Earth.

The scientists therefore suggest that the Drake equation should be better defined so it takes account of how many planets have continents and oceans and long-lasting plate tectonics. If it is, then the estimate becomes much lower: the important variable goes from nearly 100 per cent to between between 0.003 per cent and 0.2 per cent.

“This explains the extreme rareness of favorable planetary conditions for the development of intelligent life in our galaxy and resolves the Fermi paradox,” said University of Texas at Dallas’s Robert Stern, who wrote the paper alongside Taras Gerya from the Swiss Federal Institute of Technology in Zurich.

The work is reported in a new paper, ‘The importance of continents, oceans and plate tectonics for the evolution of complex life: implications for finding extraterrestrial civilizations’, published in the journal Scientific Reports.