The Solar System might not be as quiet and orderly as we think. Imagine one day looking up and seeing something strange in the sky, a small speck that grows larger and larger. Soon, it becomes clear: ...

There’s a bit of a paradox about our galaxy: it’s both jam-packed with stars and cavernously empty. The Milky Way is crowded in the sense that it holds hundreds of billions of stars, as well as ...

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

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 ...

This discovery was made by two of NASA’s most celebrated telescopes. This illustration provided by Dan Durda shows the exoplanet Kepler-1625b with a hypothesized moon. On Thursday, Oct. 4, 2018, two ...

Our solar system is a smashing success. A new study suggests that from its earliest period—even before the last of its ...