Radio and television signals travel at the speed of light. With Gliese 581g being 20 light years away from Earth, our radio and television transmissions from 20 years ago are just reaching the planet. This means that extraterrestrials could be watching the Arsenio Hall Show and Cheers, or listening to Sinead O’Connor and Bell Biv Devoe.This assumes, however, that the inhabitants of Gliese 581g have the technology to receive and interpret Earth’s signals. So could Earthlings watch 20-year-old TV from an alien planet like Gliese 581g? Again, it comes down to technology. SETI (the Search for Extraterrestrial Intelligence) is an organization on Earth searching for incoming signals from other planets. Seth Shostak, SETI senior astronomer, told Fox News, “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.”
If residents of Gliese 581g are able to watch our decades-old television shows, let’s hope they have a sense of humor when watching reruns of shows like Alf and Mork and Mindy . . .