When sonar first picked up a massive, stair‑like object on the floor of the Baltic Sea, the image looked less like geology and more like a movie prop. The structure’s circular outline, sharp edges and ...

There are three ways to look for evidence of alien technological civilizations. One is to look out for deliberate attempts by them to communicate their existence, for example, through radio broadcasts ...

Add Yahoo as a preferred source to see more of our stories on Google. A NASA satellite image of the sky, with a hot, dusty galaxy circled in magenta. A team of astronomers combed through a collection ...