The question of whether life outside of this Earth actually exists has been a debate for the record books. However, many today believe that there is, in fact, life outside of the Earth but we just haven't found it yet. NASA's top scientist now predicts that we will find signs of alien life by 2025, with even stronger evidence to come in the years that follow.
"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 Tuesday during a panel event on water in the universe. "We know where to look. We know how to look."
"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."
Stofan wasn't alone in this opinion, and many on the panel agreed.
"It's definitely not an if, it's a when," said Jeffery Newmark, NASA's interim director of heliophysics.
When we do finally find evidence of life, however, it won't necessarily come from signs of an alien civilization. Instead, it will probably be something much, much smaller.
"We are not talking about little green men," Stofan says. "We are talking about little microbes."
The claims echo one made at a similar event last year when NASA astronomer Kevin Hand also predicted a big discovery.
"I think in the next 20 years we will find out we are not alone in the universe."
How will scientists find this life?
"With new telescopes coming online within the next five or 10 years, we'll really have a chance to figure out whether we're alone in the universe," astronomer and director of Cornell University's search for distant habitable planets, Lisa Kaltanegger said. "For the first time in human history, we might have the capability to do this."
For years, scientists have assumed all stars have what is known as a habitable zone - an area close enough to a star where water doesn't freeze or boil away, allowing liquid water to exist. In recent years, scientists have found about 1,800 planets outside of our solar system, and many that reside in the foreign stars' habitable zones.
Scientists now believe that there could be billions of planets in the Milky Way galaxy opening up the possibility that there is life somewhere else just waiting to be discovered.
