In an extraordinary new development, NASA astronaut and second man on the moon Buzz Aldrin reportedly has passed a lie detector test after saying he had witnessed a UFO personally while on a mission. He was one of several people to talk about their experiences under lab conditions, along with fellow astronauts Al Worden, Edgar Mitchell, and Gordon Cooper. But unfortunately for alien enthusiasts, it probably does not do much to bolster their case.

The 88-year-old astroanut has said on several occasions that while traveling to the moon in a spaceship, he saw “something out there that was close enough to be observed … sort of L-shaped,” according to reports. A later lie detector test proved that Aldrin was telling the truth about the encounter. Worden, who was on Apollo 15, and Mitchell, who was on Apollo 14, also claimed to have seen UFOs.

But before you get all excited about this proving the existence of alien life, keep in mind that even Aldrin himself was skeptical, saying that there were many possible explanations for what he saw that do not involve alien life.

“On Apollo 11 in route to the Moon, I observed a light out the window that appeared to be moving alongside us,” he said in a question and answer session on Reddit back in 2014 when a user specifically asked him if he believed in aliens. “There were many explanations of what that could be, other than another spacecraft from another country or another world – it was either the rocket we had separated from, or the 4 panels that moved away when we extracted the lander from the rocket and we were nose to nose with the two spacecraft. So in the close vicinity, moving away, were 4 panels. And i feel absolutely convinced that we were looking at the sun reflected off of one of these panels. Which one? I don’t know. So technically, the definition could be ‘unidentified.'”

Aldrin said they when they returned, they debriefed and explained exactly what they had observed.

“And I felt that this had been distributed to the outside world, the outside audience, and apparently it wasn’t, and so many years later, I had the time in an interview to disclose these observations, on another country’s television network,” Aldrin said. “And the UFO people in the United States were very very angry with me, that i had not given them the information. It was not an alien. Extraordinary observations require extraordinary evidence. That’s what Carl Sagan said.”

Which is not to say that he does not believe in aliens at all. On the contrary, Aldrin believes that the existence of aliens somewhere in our universe is a near certainty.

“There may be aliens in our Milky Way galaxy, and there are billions of other galaxies,” he said. “The probability is almost CERTAIN that there is life somewhere in space. It was not that remarkable, that special, that unusual, that life here on earth evolved gradually, slowly, to where we are today.”

But will we ever meet them? It seems pretty doubtful, at least in our lifetimes, he said.

“The distances involved in where some evidence of life may be, they may be hundreds of light years away,” he added.