Everything we know about the universe suggests Earth is not unique. There could be as many as 40 billion other Earth-like planets in our galaxy alone.
With those kinds of stats, the odds that life exists somewhere else in the universe are pretty darn high.
The problem? We're just not searching for it the right way, according to Nathalie Cabrol, director of the Carl Sagan Center for Research at the Search for Extraterrestrial Intelligence (SETI) Institute.
Cabrol recently wrote an opus outlining how we need to overhaul our current alien-hunting techniques if we want to get serious about finding life beyond Earth.
"To find [extra-terrestrials], we must open our minds beyond a deeply rooted, Earth-centric perspective, expand our research methods and deploy new tools," Cabrol said in a statement.
"Never before has so much data been available in so many scientific disciplines to help us grasp the role of probabilistic events in the development of extraterrestrial intelligence," she added. "These data tell us that each world is a unique planetary experiment. Advanced intelligent life is likely plentiful in the universe, but may be very different from us, based on what we now know of the coevolution of life and environment."
Here are some of our biggest pitfalls in hunting for aliens, and how we can fix them, according to Cabrol:
We shouldn't assume we'll find aliens that look like us.
"In our quest to find ET, we have only been searching for other versions of ourselves, making the odds of success possibly more daunting than already dictated by nature," Cabrol writes.
Humans aren't even the typical life form on our own planet. Compared to all the other types of life here, we're a statistical outlier.
We're not thinking about making contact the right way.
"Ultimately, to find aliens, we must become aliens and understand the many ways they could manifest themselves in their environment and communicate their presence," Cabrol writes.
Right now, a lot of SETI efforts use radio telescopes to listen for extraterrestrial signals. However, it's entirely possible that alien life can't communicate in radio waves, and we could be missing another signal they're trying to broadcast to us.
"Most advanced alien species will likely have developed forms of communication completely unrecognizable to us," Cabrol points out.
We also get excited every time someone detects "biosignatures" on distant planets outside our solar system. However, just because we find traces of oxygen or carbon in the atmosphere of an exoplanet, that doesn't necessarily make it any more likely to support life than another planet. There could be life forms out there that don't need oxygen to live, and thrive instead on another elements.
We need a new alien-hunting club.
For the last 50 years that we've used radio telescopes to listen for signals, the universe has been deafeningly silent.
Cabrol proposes creating a "Virtual Institute" within the SETI Institute as a way to broaden our search efforts and allow scientists around the world to contribute.
"The fact is that we embarked on this journey only a few decades ago and have applied to it very limited tools and detection strategies," she concludes. It's no wonder we haven't found anything yet.
Bottom line: Our search for aliens has only just begun. And we're realizing we need to cast a wider net.