Reviews | Written by Nigel Watson 09/10/2019



The paradox is that in every nook and cranny of our own planet is teeming with life but the rest of the Universe seems devoid of it.

The Drake Equation, formulated by Frank Drake in the early 1960s, summarised the main factors that might produce civilisations capable of sending out signals in our galaxy. Using his equation, he estimated between 1,000 and 100,000,000 such civilisations could be in existence. If the Drake Equation is correct, many civilisations should have had plenty of time to build interstellar spaceships and should be here already. The Fermi Paradox is that, despite the very high probability of life out there, we have failed to detect any signals from technologically-advanced aliens.

Keith Cooper, the editor of Astronomy Now, sets out many of the reasons why we have not heard a peep from our galactic neighbours and challenges the assumptions that SETI (Search for Extraterrestrial Intelligence) researchers use to detect life out there.

The worst scenario is that the conditions on earth are so rare that no other planet has been capable of sustaining life as we know it. Not only are we in the habitable zone that is not too far or too close to our sun that it has the right temperature to support liquid water and a suitable atmosphere for life, but we have a moon that came into existence in a rare set of circumstances and has helped keep the earth’s rotation stable. Besides that, earth’s plate tectonics activate a carbon-silicate cycle that regulates the amount of carbon dioxide in the atmosphere, which absorbs heat from the planet’s surface and keeps the atmosphere warm.

Even if earth is not rare, Cooper discusses why extraterrestrials might attempt to contact us and, if they did send a message, what would they tell us? He also notes that SETI research tends to assume that intelligent beings will evolve and use technology much like our own. As Cooper notes, “the Universe is not obliged to deliver on what we hope or wish it to be. Our mainstream depictions of what we expect extraterrestrial intelligence to be like insidiously introduce bias right under our very noses.” As a consequence, he thinks we need to widen our anthropocentric assumptions to better define what we are looking for in the stars.

This is an entertainingly well-written, fact-filled dive into the world of SETI that explores where it should go in the future and what the consequences might be if we do contact ET.