The search for extraterrestrial intelligence could yield proof of its existence within 25 years, a U.S. scientist involved in the quest says.

Speaking at the SETI Con convention in Santa Clara, Calif., Seth Shostak -- senior astronomer at the Search for Extraterrestrial Intelligence Institute in Mountain View, Calif. -- said, "I actually think the chances that we'll find ET are pretty good," SPACE.COM reported Monday.

"Young people in the audience, I think there's a really good chance you're going to see this happen," he said.

The SETI search will take a giant step forward when the Allen Telescope Array, a network of radio dishes under construction in northern California, is fully operational, Shostak said. By 2015, the array should be able to scan hundreds of thousands of stars for signs of extraterrestrial intelligence, he said.

Detecting an alien signal within 25 years is one thing, but figuring out the message could take much longer, Shostak said.

An alien civilization would likely be as technologically advanced compared to us as Homo sapiens are to our hominid relatives Neanderthals, he said.

"We could give our digital television signals to the Neanderthals, and they'll never figure it out. And they're not stupid," he said.