cosmos

Carl Sagan's life, verified quirks, and scientific legacy: the Voyager Golden Record, marijuana essays, nuclear winter, and billions and billions of stars.

The Moon's origin is reconstructed from rocks, its interior, and orbital models. A giant impact leads the explanation, but the precise scenario is uncertain.

Mars is the most explored planet beyond Earth: home to the largest volcano in the solar system, a canyon system thousands of kilometers long, and clear evidence that it once hosted flowing water. Here is what science has revealed.

About 4.57 billion years ago, a cloud of gas and dust collapsed under its own gravity. Out of the disk it left behind came the Sun, eight planets, hundreds of moons, and the debris belts of our cosmic neighborhood.

For two centuries, Newton's gravity was the gold standard. Then Einstein showed that gravity isn't a force at all — it's the curvature of spacetime itself. Here's what that actually means, and how it has been tested.

Pulsars produce repeating signals as neutron stars rotate. Their timing helps researchers study binary orbits and search for gravitational-wave backgrounds.