Astronomy

34 ASTRONOMY • SEPTEMBER 2017

It’s never aliens. Until it is.

That’s been the story for the nearly

60 years the Search for Extraterrestrial

Intelligence (SETI) has been officially

underway. You can stretch that date

back even further if you count a 1924

military campaign to listen for radio

signals from Mars as it reached its

closest opposition in more than a

century. But in all that time, we’ve come

up with nothing.

Thanks to Yuri Milner, a venture

capitalist who made billions through

big tech investments, more money than

ever is going into SETI research. Milner

initiated an investment of $10 million a

year for a decade in 2015, all with the

hopes of finally hearing an alien signal.

That process may involve a few

false positives, for which an

all-too-earthly cause

is ultimately

found. They can add themselves to this

list: a guide to many of the times we

thought maybe, just maybe, we were

finally no longer alone in the universe.

For decades, humanity has been searching for aliens.

Here are the false alarms. by John Wenz; illustration by Theo Cobb

John Wenz is an associate editor of

Astronomy magazine.