Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in ...

About 4.6 billion years ago, a celestial cloud collapsed, paving the way for our solar system to form. Then, a nebula with strong gravitational pull took shape, kick-starting the birth of the sun. But ...

As telescopes have become more powerful, it’s turned out our solar system is not the only game in town: There are millions of other planets out there in the galaxy. But we’re still teasing out clues ...

For centuries our solar system was the only planetary system known to humans. We had no proof other worlds existed beyond those in our own cosmic backyard, and we imagined that if other planetary ...

As J.R.R. Tolkien wrote in The Fellowship of the Ring, “Not all those who wander are lost.” But in the case of planets, it’s possible that most of them are. Rogue planets—planets that are adrift in ...