Based on the composition of gases spewed by the icy space rock, researchers estimate that our guest might be up to 12 billion ...

New measurements of radio galaxies reveal that the solar system is racing through the universe at over three times the speed predicted by standard cosmology. Using highly sensitive data from multiple ...

Most of us learned the basics of our solar system in school. Eight planets, one sun, some moons, a couple of asteroid belts. It sounds orderly, even sensible. The trouble is that once you look past ...

Billions of years ago, while the solar system was still young, a massive object may have drifted into it. It's not a spaceship, but it is an alien visitor in its own right—a colossal interstellar body ...

While life on Mars (and Venus) has long been an obsession for those wondering if we're alone, there are other places in our ...

It may not feel like it, but everything in the universe is in constant motion. Our Sun, with all its planets, orbits the center of the Milky Way, flying through the cosmos at around 450,000 miles per ...

Just the third-ever confirmed interstellar object has been detected in our solar system. Here's what we know. (Spoiler: It's not aliens.) The interstellar comet, originally called A11pl3Z and now ...