Mon Apr 21, 8:31 PM ET
Alien life may well exist in a primitive form somewhere in our corner of the galaxy, famed astrophysicist Stephen Hawking said Monday.
Given the size of the universe, it is unlikely that Earth is the only planet to develop some sort of life, Hawking told an audience at George Washington University in Washington, D.C. He added that humanity must embrace space exploration, if only to ensure its long-term survival.
"While there may be primitive life in our region of the galaxy, there don't seem to be any advanced intelligent beings," said Hawking during a lecture as part of a series commemorating NASA's 50th anniversary this year.
The lack of success by the Search for Extra-Terrestrial Intelligence (SETI) project to discover signals from an alien civilization suggests that none exist within several 100 light-years of Earth, Hawking said, though he offered three theories on the dearth of interplanetary communications.
The probability of primitive life developing on a suitable planet may be extremely low, or it may be high, but aliens intelligent enough to beam signals into space may also be smart enough to build civilization-destroying weapons like nuclear bombs, he said. More likely, he added, is that primitive life is likely to develop, but intelligent life as we know it is exceedingly rare.
"We don't appear to have been visited by aliens," Hawking said, adding that he discounts reports of UFOs. "Why would they only appear to cranks and weirdoes?"
Alien life aside, Hawking said humanity must pursue a long-term effort of space exploration that would span hundreds of years in order to ensure the survival of the species. He likened those opposed to spending money on space science and exploration to those who wrote off Christopher Columbus' trans-Atlantic Ocean voyage in 1492 as a waste of money.
"The discovery of the New World made a profound difference on the old. Just think, we wouldn't have had a Big Mac or KFC," Hawking said.
"Spreading out into space will have an even greater effect," he added. "It will completely change the future of the human race, and maybe determine whether we have any future at all."
Hawking, 66, is a renowned theoretical physicist and cosmologist who suffers from the neurological disorder amyotrophic lateral sclerosis (ALS). He uses a wheelchair, communicates with the aid of a computer, and co-wrote a children's book about science - "George's Secret Key to the Universe" - with his daughter Lucy in the hope of inspiring youth to pursue studies in science and technology.
"We live in a society that is increasingly governed by science and technology," Hawking said. "Yet fewer and fewer people want to go into science."
Sending astronauts back to the moon, establishing a lunar base with a clear target of going on to Mars would do much to restore the public's support for spaceflight, he added.
"If the human race is to continue for another million years we will have to boldly go where no one has gone before," Hawking said.I couldn't agree more