How easy it is to scoff at 'desperate' seekers of aliens, as the science-fiction writer Brian Aldiss did in these pages two years ago (Nature 409, 1080; 2001). He touched some nerves: aliens are indeed as real as ghosts or numerous deities (in other words, they continue to be purely imaginary); their fictitious portrayals impede understanding; their air of being the product of scientific thinking is indeed spurious. But when all was said and done, his put-down, although erudite, was ultimately no more than a stimulating polemic.

Other prominent sceptics have been more soberingly analytical. Peter Ward and Donald Brownlee, in their book Rare Earth (Copernicus/Springer, 2000), discussed various factors that, on the face of it, conspire to make the emergence of life around stars probable but the appearance of intelligent species almost impossible. “Is that it?”, one might ask when faced by the likelihood that we are, alas, the pinnacle of our Galaxy's intelligence. And according to a theory discussed at last week's meeting of the American Association for the Advancement of Science, if it wasn't for the chance mutation of the FOXP2 gene 50 millennia ago, we wouldn't have the creativity to explore these ideas.

Yet more cold water has been poured on our hopes that we have intelligent company in a recent collection of answers to Enrico Fermi's pointed question about the lack of visitors: “Where is everybody?”. In a sceptical book of that title (Copernicus/Springer, 2002), Stephen Webb's explanations for the absence of alien visitors range from: “They are here and they call themselves Hungarians”, attributed to Budapest-born physicist Leo Szilard, to: “Science is not inevitable”, science being one of many improbable developmental steps from primitive organisms to interstellar communication or travel.

A pox on such pan-Galactic pessimism. These arguments may give sober government agencies an excuse to stop funding searches for extraterrestrial intelligence (SETI), as the US Congress did over a decade ago. But the rest of us should look more favourably on such expressions of the fundamental yearnings of humanity. All credit to the likes of William Hewlett, David Packard and Paul Allen, whose funds have allowed the SETI projects to establish new technologies — albeit still pitifully insensitive if we are to detect the equivalent of Friends leaking through some planetary ionosphere 1,000 light years away. All credit too to the tens of researchers who devote themselves to the dispiriting quest for such electromagnetic detritus. The rest of us should drag ourselves away from revivals of ET, Close Encounters and Taken long enough to scan the latest ambitions of the SETI institute, outlined in SETI 2020 (http://www.seti.org), and send it a donation for the hunt for the real Thing.