The SETI Institute has examined this star system using its Allen Telescope Array, searching for transmissions over a wide range of the radio dial, from 1 to 10 GHz. So far no dice, although we will surely keep trying.

But the fact that we’ve not yet picked up radio noise from this sibling world is hardly discouraging. To begin with, Kepler 186f is nearly 500 light-years away, which is a fair piece, even for astronomers. To detect radio signals with the Allen Array would require aliens wielding a transmitter of at least 100 million watts, mounted on an antenna the size of a football field. They’d also have to train the antenna in our direction.

But of course, they don’t know about Homo sapiens, so their incentive to beam signals our way is probably small.

Kepler 186f: Is It Inhabited?