For centuries, scientists have searched the universe for cosmic clues as to whether or not we are alone. According to new estimates, there may be more active civilizations out there—but not many.

The Drake equation, established by astronomer Frank Drake in the 1960s, is a formula that many researchers use to estimate the probability that we will interact with extraterrestrial civilizations in our galaxy, the Milky Way.

Drake’s seven critical variables, which vary from the number of habitable planets and exoplanets in the galaxy to the amount of time it takes for intelligent life to develop, are almost impossible to pin down. The formula works more like a framework for estimating the likelihood of finding life; previous predictions ranged from zero to over a billion civilizations.

Working under the assumption that life takes the same amount of time to evolve in the far reaches of the galaxy as it does here on Earth, a pair of researchers from the University of Nottingham in the United Kingdom have narrowed that estimate to just 36 extraterrestrial civilizations.

“There should be at least a few dozen active civilizations in our galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth,” astrophysicist Christopher Conselice explained in a press statement. This calculation was dubbed the “Astrobiological Copernican Limit” by the researchers.

Using this computation as a guide, the scientists developed many scenarios: on one end of the spectrum is a weak scenario in which intelligent life develops in less than 5 billion years, while on the other end is a strong scenario in which intelligent life forms in between 4.5 and 5.5 billion years.

According to the scientists’ calculations for the strong scenario, there should be anywhere from four to 211 complex civilizations capable of launching signals out into orbit, with 36 being the most likely. The closest of these complex civilizations should be about 17,000 light-years away, orbiting a low-mass M-type dwarf star.

This, unfortunately, does not speak well for our chances of communicating with distant extraterrestrials. With today’s technology, communicating across such vast distances is impossible.

Not everyone buys the analysis, which was published in The Astrophysical Journal. According to the Guardian, some researchers are wary about the work. Before accepting the new discoveries as fact, Oliver Shorttle of the University of Cambridge told the news organization that further factors, such as how exactly life formed on Earth, needed to be considered.

So, what does this have to do with the future of life on Earth? The quest for life elsewhere in the universe will reveal insight into our own fate.

“If we find that intelligent life is common then this would reveal that our civilization could exist for much longer than a few hundred years,” Conselice said. “[A]lternatively if we find that there are no active civilizations in our Galaxy it is a bad sign for our own long-term existence.”