Add Yahoo as a preferred source to see more of our stories on Google. (cokada/iStock/Getty Images) Alien megastructures built to harvest stellar energy or alter the orbits of stars may be physically ...

O’Neill cylinders are often imagined as giant rotating megastructures built to house humanity in space. But this episode explores the deeper challenge behind them: not how to make them spin, but how ...

If you’re trying to come up with the best game plan for proving the existence of extraterrestrials, you’ve got plenty of options. Naturally, you want a strategy with a high chance of success, simply ...