NASA scientists say that not only is it unlikely we are alone in the universe, but we are possibly closer than ever before to knowing where to look for signs of life in the solar system and beyond.
It's approaching a matter of when, not if, NASA officials say.
"I believe we are going to have strong indications of life beyond Earth in the next decade and definitive evidence in the next 10 to 20 years," said the space agency's chief scientist Ellen Stofan, speaking at a public panel held in Washington, D.C.
The panel featured speakers setting forth the space agency's ongoing efforts to look for habitable words that might harbor alien life.
"We know where to look. We know how to look," Stofan said. "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."
The odds of finding life beyond Earth have also been bolstered by recent studies confirming the presence of water, considered one keystone for the existence of life, in our solar system and on distant exoplanets, NASA says.
For example, NASA researchers say, an analysis of the atmosphere above Mars' polar ice caps suggests 50 percent of the planet's northern hemisphere may once have had oceans a mile deep, and that water existed for a long period of time -- as long as 1.2 billion years.
That could have been long enough for complex life to form, although that shouldn't get anyone thinking about alien invasions coming from distant worlds, Stofan said.
"We are not talking about little green men," she said. "We are talking about little microbes."
Other studies have confirmed a large liquid ocean exists beneath the frozen, icy crust of Jupiter's moon Ganymede.
Such findings suggest there is reason to be optimistic about how soon we may find strong evidence of the existence of alien life, said former astronaut John Grunsfeld, now the associate administrator for the agency's Science Mission Directorate.
"I think we're one generation away [from finding it] 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 during the Washington, D.C., event.
Our solar system isn't alone in harboring the water that so many scientists see as a key to finding life, other NASA scientists said, pointing out that water has been detected in the interstellar clouds from which planetary systems and stellar systems form.
The Milky Way is "a soggy place," said Paul Hertz, director of NASA's Astrophysics Division.
