Astrobiologists propose that alien civilizations need accessible coal deposits to industrialize exoplanets and become detectable from Earth.

There are many attempts to get humanity to be found by extraterrestrial civilization, such as the In considering how many hostile extraterrestrial civilizations are in the galaxy, Alberto Caballero, ...

As technological societies advance, their energy demands skyrocket, pushing them up the Kardashev scale. While fossil fuels, wind, and solar power offer solutions, they’re limited by efficiency, ...

It's one of the biggest unanswered questions in science: if there's life beyond Earth, why hasn't it contacted us yet? Now, a scientist claims to have the answer – and it suggests aliens are more ...