THE search for extraterrestrial intelligence (SETI) could be taking the wrong approach. Instead of listening for alien radio broadcasts, a better strategy may be to look for giant structures placed in orbit around nearby stars by alien civilisations.
“Artificial structures may be the best way for an advanced extraterrestrial civilisation to signal its presence to an emerging technology like ours,” says Luc Arnold of the Observatory of Haute-Provence in France. And he believes that the generation of space-based telescopes now being designed will be able to spot them.
Arnold has studied the capabilities of space-based telescopes such as the European…
