|Michael Lemonick reports that Avi Loeb has an unorthodox new idea about how to search for alien civilizations ... and it is hardly a surprise. Loeb, who chairs the astronomy department at Harvard University, has spent much of his career thinking about how the first stars came to life after the big bang, and how galaxies were born. But lately he has become intrigued with the search for extraterrestrial intelligence, or SETI, and he tends to come at it in unusual ways.|
Over the past few years, for example, Loeb has suggested searching for aliens by looking for artificial lighting on Pluto, in the admittedly unlikely event that extraterrestrials (ET) have set up an outpost there. He also has proposed trying to detect industrial pollution on distant exoplanets. His latest notion, laid out in a paper he and a co-author just put online ... suggesting that we should look for the microwave beams ETs might use to send light sails wafting between the planets in their home solar systems. I do not think it is nuts, says Seth Shostak, senior astronomer at the SETI Institute in California. It is a clever idea.
Light sails themselves are an actual thing, at least in theory ... they use huge sheets of ultrathin Mylar to catch the solar wind, allowing them to carry a payload across interplanetary space without rockets. A prototype is now in the works sponsored by the Planetary Society, which has already flown a test mission and hopes to do a full-fledged demonstration flight next year..
The probability of success is difficult to estimate, wrote co-authors Giuseppe Cocconi and Philip Morrison in 1959, but if we never search, the chance of success is zero, they said.