Life In Space: 8 Quotes From NASA Scientists About Possibility Of Alien Life In The Universe

NASA scientists announced the discovery of seven Earth-sized planets orbiting in a habitable zone only 40 light years from Earth on Wednesday. At least three of them could have oceans, increasing the potential for life outside our solar system.

As the search for life in the universe advances, here’s what some notable scientists think about the possibility of extraterrestrials, whether or not we should talk to them and what the future holds for humanity and alien life forms.

“It doesn’t seem unreasonable to think that we are not alone, if all those planets are completely sterile, you’ve got to think, wow there must be something really special and miraculous about Earth — but generally those people are not scientists.” Neil deGrasse Tyson, astrophysicist and cosmologist

“I believe that there is life all over our universe, since it would be the height of arrogance to think that we are alone. Moreover, I believe that at some point, life on Earth will die out, either from natural causes, or from our own doing…I believe that life is always starting in some parts of the universe at the same time that it is dying out in others. We don’t know about each other, simply because the distances are so vast.” Leroy Chaio, former NASA astronaut and commander aboard the International Space Station

“Any civilization detecting our presence is likely to be technologically very advanced and may not be disposed to treat us nicely.” Mark Buchanan, physicist

“There could be 10 billion civilizations or none. The evidence is certainly none. The evidence says no one’s out there.” William Borucki, NASA scientist and principal investigator of NASA’s Kepler mission

“One day we might receive a signal from a planet…but we should be wary of answering back. Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn’t turn out so well.” Stephen Hawking, theoretical physicist and cosmologist

“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. 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.” Ellen Stofan, NASA chief scientist

“At the moment, life on Earth is the only known life in the universe, but there are compelling arguments to suggest we are not alone. Indeed, most astrophysicists accept a high probability of there being life elsewhere in the universe, if not on other planets or on moons within our own solar system. The numbers are, well, astronomical: if the count of planets in our solar system is not unusual, then there are more planets in the universe than the sum of all sounds and words ever uttered by every human who has ever lived. To declare that Earth must be the only planet in the cosmos with life would be inexcusably egocentric of us.” Neil deGrasse Tyson

“It’s definitely not an if, it’s a when.” Jeffrey Newmark, interim director of heliophysics at NASA