We know we're not alone. We just don't know who or what is out there. Oh, or where.
So we've speculated and watched movies and read books that all point to little green creatures with slightly pointed heads.
President Bill Clinton would like to reassure us.
In an appearance on the Jimmy Kimmel show on Wednesday, he explained that when he came to office in 1993 he took a look at all the classified files on UFOs.
"We had the anniversary of Roswell," he said. You know, that Roswell. Because why wouldn't a flying saucer be tooling around the New Mexico desert in the late 1940s? He added that there was chatter, too, about oh-so-secret Area 51, in equally forlorn Nevada.
"First, I had people go look at the records on Area 51 to make sure there was no alien down there," he said. Which is reassuring. No evidence of aliens was found.
"When the Roswell thing came up, I knew we'd get zillions of letters," he continued. "So I had all the Roswell papers reviewed. Everything."
He insisted that if he had seen evidence of aliens, he would tell Kimmel. Right there, right then. Cross his heart and all that.
That doesn't mean the former president is an alien skeptic. Quite the reverse.
He said: "We know there are billions of stars and planets literally out there. And the universe is getting bigger. We know from our fancy telescopes that just in the last two years more than 20 planets have been identified outside our solar system that seem to be far enough away from their suns -- and dense enough -- that they might be able to support some form of life."
"So it makes it increasingly less likely that we're alone," was his deduction.
Clinton still insisted he didn't know whether aliens actually do exist. "But if we were visited some day, I wouldn't be surprised," he said.
Naturally, he hoped it wouldn't be like the movie "Independence Day." After all, his wife might be in the White House. Which would mean he would be very near her office. Which would mean, oh, no, let's not think about that.
He concluded by suggesting that an alien invasion might be the only way to unite increasingly divided humans -- miserable, self-centered wretches that we are.
"Think of how all the differences on Earth would seem small if we felt threatened by a space invader," he concluded.
It was Stephen Hawking who suggested that aliens might hate us.
Even so, I cannot imagine that even if they were about to descend upon us to rip us to shreds, this would suddenly cause Dick Cheney and Joe Biden to agree on something.