Intelligent aliens, if they exist in the galaxy or the Universe, might be detectable from a variety of signals: electromagnetic, from planet modification, or because they’re spacefaring. But we haven’t found any evidence for an inhabited alien planet so far. We may truly be alone in the Universe, but the honest answer is we don’t know enough about the relevant probabilities to draw definitive conclusions. Our first discovery of life beyond Earth still awaits. (Credit: Ryan Somma/flickr)

The unsurprising non-detection of intelligent aliens

Life arose on Earth very early on. After a few billion years, here we are: intelligent and technologically advanced. Where’s everyone else?

If you’ve ever gazed up at a dark and clear night sky, you might feel the same thing that I do each and every time: a feeling that it’s beckoning us and drawing us in to explore and wonder what’s out there in the great abyss of space. Each point of distant, twinkling light isn’t just a star in its own right, but also a chance: for planets, for biochemistry, and for life. If we really allow our imaginations to run wild, we might even imagine the existence of something better than mere life, such as the existence of intelligent, self-aware, and technologically advanced civilizations.

But that brings up a question that humanity has obsessed over for generations: If the ingredients for life are common, and we evolved naturally, then where is everyone else? Many of you consistently write in with variations on this question, including Franco Camporeale, Oleg (Alex) Naum, and Zoe Eppley, asking things like:

The Fermi Paradox has come up a few times in my recent reading…do the following things have anything to do with the possibility of life beyond Earth?