Humanity has already flung machines into interstellar space, but sending people is a different problem entirely. The physics of propulsion, the fragility of the human body, and the sheer size of the ...

Realising that our solar system isn’t like most others out there has helped astronomers rewrite the story of how it formed ...

Add Yahoo as a preferred source to see more of our stories on Google. The Oort Cloud, an expanse of icy bodies in the far reaches of our solar system, is shown here in a scene from "Encounters in the ...