NASA/Danielle Futselaar/Tomas Griger

If there are other technologically advanced civilizations in our corner of the cosmos, they're pretty quiet.

That's the finding of the Breakthrough Listen initiative, which released nearly a petabyte of data this week from radio observations of 1,327 nearby stars over the past three years. An analysis of that data is also laid out in two new papers (here and here) submitted to academic journals.

The bottom line is that all the signals picked up by the team using the Green Bank and Parkes Radio telescopes in West Virginia and Australia, respectively, can be attributed to either natural sources or our own human technology.

"We scoured thousands of hours of observations of nearby stars, across billions of frequency channels," Breakthrough Listen project scientist Danny Price said Wednesday in a statement. "We found no evidence of artificial signals from beyond Earth, but this doesn't mean there isn't intelligent life out there: we may just not have looked in the right place yet, or peered deep enough to detect faint signals."

Although the new results contain no alien broadcasts, Breakthrough Listen claims this still amounts to the "most comprehensive and sensitive radio search for extraterrestrial intelligence (SETI) in history."

Alien believers should definitely stay tuned because the initiative is just getting started.

In the near future, it plans to present results for higher frequencies, more signal types and a sample of a full million stars with the help of the MeerKAT telescope in South Africa.

Originally published June 20, 7:46 a.m. PT.