In “Star Trek” lore, humans meet their first aliens in 2063. It turns out that we might not need to wait that long — at least according to some optimistic scientists who claim that we should find evidence of alien life within the next two decades.
"I think in the next 20 years we will find out we are not alone in the universe.”
Those words, from Kevin Hand, deputy chief scientist for solar system exploration at NASA’s Jet Propulsion Laboratory, made headlines on Monday when he spoke them during a panel discussion.
Sign up for Science news delivered to your inbox
He's not the first one to make predictions of that kind. Russian astronomer Andrei Finkelstein gave the same time frame three years ago, and Seth Shostak, senior astronomer at the SETI Institute, has said we will discover a signal from intelligent life by 2025, only 11 years from now.
Later, Hand told NBC News that he stood by his statement. Between the search for signals from alien civilizations, advanced telescopes examining atmospheres of exoplanets — planets that orbit stars other than the sun — and potential missions to Europa and Enceladus (the water-covered moons of Jupiter and Saturn, respectively), he said, it’s not a stretch to think that we might find signs of life relatively soon.
“There are not tremendous technological hurdles to getting this kind of exploration done,” Hand said. “It’s not like we have to develop warp drive to search for life on Mars and Europa.”
"There is one thing we can say for sure: If we don’t look for life out there, we won’t find it."
It’s more a matter of will than scientific know-how, he said. NASA’s $8.8 billion James Webb Space Telescope is a good start. Slated to launch into orbit by 2018, it could detect signs of oxygen, methane or other signs of biological life on distant planets, although some scientists think that an even larger, more advanced telescope is needed to accomplish that goal.
NASA’s Curiosity rover, currently exploring Mars, could still find that the Red Planet was once home to life.
But not all scientists are willing to name a specific number of years until we find traces of aliens — or if we will ever find them at all.
“Kevin Hand is a brilliant scientist, and the search for other life in the universe is probably the greatest human quest there is,” Berkeley astronomer Geoffrey Marcy, who has discovered more exoplanets than anyone else on Earth, told NBC News.
“Having said that, we don’t know if life exists elsewhere,” he said. “This is a quest for a holy grail that might be easy to find, or it might be that life in the universe is extraordinarily rare. We have no idea which of those two possibilities might be true.”
There are theories as to how common life is in the universe. But until we actually observe signs of life, we can’t be sure, he said. If we do find something in the next 20 years, however, it could mean that we have a lot of alien neighbors.
“If you put your toe into the ocean and a shark bites it off, you can bet that there are other sharks out there,” Marcy said. “If we put our toe into the cosmic ocean and we make contact with life, that could be a sign that the universe is teeming with it.”
While the two scientists might not agree on everything, they both believe human beings should be putting more resources into exploring space for signs of life.
Finding it anywhere could mean "we live in a biological universe where life arises whenever the conditions are right," Hand said.
The possibility of such a revolutionary discovery is worth funding advanced telescopes and missions to Mars, Europa and beyond.
As Marcy put it, "There is one thing we can say for sure: If we don’t look for life out there, we won’t find it."