"I think we're going to have strong indications of life beyond Earth within a decade, and I think we're going to have definitive evidence within 20 to 30 years," NASA chief scientist Ellen Stofan said on Tuesday during a televised panel discussion.

"We know where to look. We know how to look," Stofan added. "In most cases we have the technology, and we're on a path to implementing it. And so I think we're definitely on the road."

Former astronaut John Grunsfeld, associate administrator for NASA's Science Mission Directorate, also shared in Stofan's prediction. "I think we're one generation away in our solar system, whether it's on an icy moon or on Mars, and one generation [away] on a planet around a nearby star," Grunsfeld said.

With liquid water below the surface of Jupiter's moons Europa and Ganymede and evidence of past water in Mars and the discovery of organic molecules - the building blocks of life - on the Red Planet, we may well be on our way.