What's on ET's TV?

How far into space have our television signals traveled? Pretty darn far. This cartoon shows which signals have reached which planets, although newly discovered Gliese 581g isn't pictured. Each ring represents five light years, meaning Gliese 581g should be watching The Arsenio Hall Show by now. (Abstruse Goose)

Will we find evidence of a real-life E.T. in the very near future? (Universal Pictures)

Astronomers say a newly discovered Earth-size planet 20 light years away may sustain life -- even intelligent life -- giving Earthlings a chance to dumb them down with some two-decades-old TV.

If they're watching us, then "Cheers" and the Cosby Show spin-off "A Different World" should just now be hitting them. And here's a big tip for alien gamblers: Bet the house on the Reds to sweep the A's in the World Series.

The new planet, named Gliese 581g, is the first Earth-like world found in a star's habitable zone -- the region where a planet's temperature can sustain liquid water on its surface. And the planet's discoverers think we're certain to find life there.

"Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 percent," said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, during a press briefing on the finding.

"I have almost no doubt about it."

Since radio and television signals travel at the speed of light, the signals we transmitted 20 years ago from Burbank to Boston sailed off the planet toward the heavens -- and should just now be reaching Gliese 581g, right?

Absolutely, said Seth Shostak, senior astronomer with the SETI Institute.

"This is all correct," Shostak told FoxNews.com, noting that 1990's era TV "would be the vintage of stuff reaching Gliese 581g now." U Cal's Vogt confirmed as well that radio waves carrying Bell Biv Devoe's "Poison," Sinead O'Connor's "Nothing Compares 2 U," and Paula Abdul's "Straight Up" should just now be reaching the planet.

So shouldn't we be watching alien TV right now too?

Shostak's colleagues at SETI -- the Search for Extra-Terrestrial Intelligence -- use massive arrays of satellite dishes to monitor the heavens for just such transmissions from extraterrestrial life. SETI's mission: to explore, understand and explain the origin, nature and prevalence of life in the universe. Shostak told FoxNews.com that his team has yet to detect any signals from Gliese 581g, however.

"We looked at this star system twice -- once using a radio telescope in Australia, and then using one in West Virginia. No signal was heard." It appears we won't see alien versions of "Murphy Brown" or "Murder, She Wrote."

But that doesn't mean aliens aren't reveling in "Full House," "Coach" and "Matlock" -- or reliving the glory days of "Mork and Mindy" and "Alf " through reruns. The group's website explains that its receivers aren't sensitive enough to catch the variation in the signal.

Those messages "would be smeared out and lost. In order to understand anything that E.T. might be saying to us, we'll have to build far larger instruments to look for the modulation of his signal."

The SETI project will continue hunting for alien life, it seems.

"When will success occur? No one knows. It could happen tomorrow, or it could take many years. Maybe it will never occur. But the only way to find out is to do the experiment."

FoxNews.com's SciTech section is on Twitter! Follow us @fxnscitech.