If smart aliens exist, they may have visited Earth millions of years ago - and left signs of their technological prowess that should be cheap and easy for us to detect.
So says astrophysicist Paul Davies of Arizona State University in Tempe. Traditionally, the search for extraterrestrial intelligence (SETI) has focused on listening for deliberate dispatches in radio signals. But in 50 years of searching, this costly approach has drawn a blank.
So Davies suggests scouring our own planet, even our cells, on the off-chance that aliens visited and did what amounts to scrawling "We were here" on the walls. "We can answer the question 'Are we alone?' without picking up messages," he says. "We may see indirect evidence of alien technology based on the footprint it leaves." Read more
Origin: lights-in-sky.blogspot.com
