A 2021 survey by the Pew Research Center found that 65% of American adults believe that intelligent life exists on other planets. While the media sometimes stereotypes believers as crackpots and conspiracy theorists, some of the greatest scientific minds in the world have gone on record expressing their support for the idea that we're not alone in the universe.
6 Famous Scientists Who Believed in Aliens
Since the early 20th century, the scientific community has discussed the possibility of life on other planets. While research continues into this area, the more significant debate seems to lie in whether aliens would be friendly visitors or hostile invaders.
1. Buzz Aldrin
Astronaut Buzz Aldrin made history in 1969 when he became the second man on the moon. In 2018, the British tabloid "Daily Star" started a rumor that Aldrin passed a lie detector test proving he encountered aliens during his mission. While Aldrin himself has denied this, he does believe that aliens are likely to exist. "There may be aliens in our Milky Way 
galaxy, and there are billions of other galaxies. The probability is almost certain that there is life somewhere in space," he said.
2. Albert Einstein
He passed away two years before the launch of Sputnik 1 in 1957, but physicist Albert Einstein was interested in space exploration throughout his life. In January 1920, a London "Daily Mail" correspondent asked Einstein about radio pioneer Guglielmo Marconi's belief in mysterious signals coming from Mars. Einstein responded, "There is every reason to believe that Mars and other planets are inhabited. Why should the Earth be the only planet supporting human life? It is not singular in any other respect. But if intelligent creatures do exist, as we may assume they do elsewhere in the universe, I should not expect them to try to communicate with the Earth by wireless [radio]. Light rays, the direction of which can be controlled much more easily, would more probably be the first method attempted."
3. Neil deGrasse Tyson
American astrophysicist and planetary scientist Neil deGrasse Tyson often gives interviews questioning whether aliens would be interested in contacting us on Earth. However, he still believes it's only logical that other planets have intelligent life. In "Death by Black Hole: And Other Cosmic Quandaries," he wrote, "If our solar system is not unusual, then there are so many planets in the universe that, for example, they outnumber 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 with life in the universe would be inexcusably bigheaded of us."
4. Stephen Hawking
British physicist and cosmologist Stephen Hawking expressed support for the idea that there is life on other planets several times throughout his career. However, in the documentary "Into the Universe With Stephen Hawking," he stated that communicating with intelligent alien life would be a significant risk to all of humankind—and that it was likely aliens would attempt to conquer and colonize every planet they could reach. "If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn't turn out very well for the Native Americans."
5. Elon Musk
Since there has been significant speculation that SpaceX founder Elon Musk is an alien himself, it's not surprising that he hasn't ruled out the possibility of intelligent life on other planets. In fact, Musk joined 27 other scientists in 2015 to sign a petition warning against active SETI (Search for Extraterrestrial Intelligence). The petition stated, "ETI's reaction to a message from Earth cannot presently be known. We know nothing of ETI's intentions and capabilities, and it is impossible to predict whether ETI will be benign or hostile."
6. Carl Sagan
American astronomer, cosmologist, and astrophysicist Carl Sagan built his career on the belief that the questioning of authority and a free exchange of ideas were critical elements in both science and democracy. While he never found definitive proof of aliens on other planets, he firmly believed that we'd one day have the answers we've been searching for. In "The Demon-Haunted World: Science as a Candle in the Dark," Sagan described how his curiosity and openness made him unique in the scientific community. "Just as there are those who accept every UFO report at face value, there are also those who dismiss the idea of alien visitation out of hand and with great passion. It is, they say, unnecessary to examine the evidence, and 'unscientific' even to contemplate the issue. I once helped to organize a public debate at the annual meeting of the American Association for the Advancement of Science between proponent and opponent scientists of the proposition that some UFOs were spaceships; whereupon a distinguished physicist, whose judgment in many other matters I respected, threatened to sic the Vice President of the United States on me if I persisted in this madness."