FIVE THINGS ABOUT A RADIO SIGNAL

1 94 LIGHT YEARS AWAY

Russian astronomers say they have discovered a radio signal 94 light years away, sparking speculation about the possibility of intelligent life. The Search for Extraterrestrial Intelligence Institute says a powerful radio telescope in Zelenchukskaya, Russia, picked up the transmission last year, but it was only recently brought to light.

2 HELLO HD 164595

The signal came from HD 164595, a solar system billions of years older than the Sun and known to have just one planet. The “Neptune- sized world” is believed to be in such a tight orbit that it’s unattractive for life.

3 NOT PROMISING

The Observer published a story on the mysterious topic entitled: “Not a Drill: SETI Is Investigating a Possible Extraterrestrial Signal From Deep Space,” setting off feverish speculation. But scientists are much, much more prosaic about the finding. “The chance that this is truly a signal from extraterrestrials is not terribly promising, and the discoverers themselves apparently doubt that they’ve found ET.”

4 ‘ INTERESTING’

But a tiny maybe is better than nothing, so “one should check out all reasonable possibilities, given the importance of the subject,” writes Seth Shostak, a Senior Astronomer at the SETI Institute, which admits “without a confirmation of this signal, we can only say that it’s ‘ interesting.’ ”

5 SERIOUS ENERGY

If the signal was aimed at our solar system intentionally, or broadcast in all directions, it would “require an effort far, far beyond what we ourselves could do, and it’s hard to understand why anyone would want to target our solar system.” In order to broadcast the signal in all directions across solar systems, Shostak says it would require 100 billion billion watts, more energy than all the sunlight falling on Earth.