This Internet Billionaire Wants to Solve the Mystery of the Universe by Barb Darrow @FortuneMagazine July 12, 2016, 7:21 PM EDT E-mail Tweet Facebook Linkedin Share icons Yuri Milner, the tech billionaire who invested early in companies from Facebook fb to Groupon grpn to Twitter twtr , is now on to bigger things: Figuring out if we, meaning human kind, are alone in the universe. Speaking at Fortune’s Brainstorm Tech conference on Tuesday, Milner said the reason he helped launch a massive effort to detect extraterrestrial signals was his (and he thinks humanity’s) need to know whether earth’s human population is the only intelligent life. Period. Last year, Milner helped revive the Search for Extraterrestrial Intelligence (SETI) effort that had been eavesdropping for radio signals that would indicate intelligent life forms somewhere other than here. Why now? “According to the latest NASA data, there are about 20 billion planets like ours, with water, just in our galaxy… and there are 100 billion other galaxies. It’s hard to believe that we’re alone,” he said. Towards that end, researchers have rented out some of the world’s most advanced radio telescopes in hopes of picking up signals that would indicate other life forms out there. “There’s a reasonable chance if another civilization reaches a certain stage, they’re using the same technology we’re using, and we can detect radio waves that they are emitting on purpose, or through leakage,” he added. Milner is also pursuing the idea of sending lots of very small space ships or probes out to grab images of Alpha Centauri or some other relatively close star, He held up a playing-card sized piece of thin plastic embedded with a microcomputer. He acknowledged that this sort of stuff is still viewed as science fiction by many. But look, he continued: “We can debate whether there’s life outside.” But given the stakes, Earth’s citizens should want to find out. Yuri Milner and Stephen Hawking Unveil Ambitious $100 Million Star-Trekking Plan It’s either yes or no. “But either answer is staggering. If we’re alone it would be time to think about not being crazy and preserving what we have here. And if we’re not alone, we should think about establishing contact,” he said. Still, researchers are not purposely sending out signals to reach other planets yet. “Sending a signal is a much more controversial subject, ” he noted. But given the amount of energy we use and radio waves we emit in the course of daily life, we may have already alerted other life forms of our presence.