Humanity has already flung machines into interstellar space, but sending people is a different problem entirely. The physics ...

Colonizing the solar system is not a single plan with a single outcome. Different goals lead to very different strategies, from mining asteroids to terraforming planets to building vast orbital ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

The workings of our solar system are roughly the same now as they have been for millions of years. Moons circle their planets, the planets circle the sun, the sun’s magnetic fields and sunspots wax ...

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 ...