A surprising new study is making a big claim: not only are we not alone in the universe, but a bunch of alien civilizations have come and gone.

Mankind has long looked to the stars and wondered if there are other forms of life out there beyond those found here on Earth, or if we really are alone in this universe. Researchers at the University of Rochester say they have the answer: no, we are not alone, and no, we can’t contact these aliens — at least not yet, according to a university statement.

The paper, published in Astrobiology, says that based on the huge number of exoplanets we’ve already found, the odds that we’re the only planet to support life are so slim as to not even be worth considering.

Science has long known about how many stars exist — the giant orbs of light are easy to spot even with the naked eye. But you need an advanced telescope to spot the exoplanets orbiting them, and until recently scientists didn’t have a good idea of just how many of these stars had solar systems of their own.

But new research suggests that about a fifth of stars not only have planets but have planets in habitable zones. This is based on data from the Kepler space telescope.

Our civilization has existed for just a blip on the astronomical scale — about 10,000 years. Based on this, scientists think that a technological society of aliens would likely have come and gone in a short span of time on another planet, and that there were likely many of these civilizations, and will probably be many more.

“Rather than asking how many civilizations may exist now, we ask ‘Are we the only technological species that has ever arisen?” Woodruff Sullivan, who is from the astronomy department and astrobiology program at the University of Washington and the coauthor of the study, said in the statement. “This shifted focus eliminates the uncertainty of the civilization lifetime question and allows us to address what we call the ‘cosmic archaeological question’–how often in the history of the universe has life evolved to an advanced state?”

“The universe is more than 13 billion years old,” he continued. “That means that even if there have been a thousand civilizations in our own galaxy, if they live only as long as we have been around — roughly ten thousand years — then all of them are likely already extinct. And others won’t evolve until we are long gone. For us to have much chance of success in finding another “contemporary” active technological civilization, on average they must last much longer than our present lifetime.”