An astrophysicist explains what wormholes are and how these theoretical space-time tunnels have popped up in the solutions to a set of decadesold equations.

This puzzle is known as the problem of time, and it remains one of the most persistent obstacles to a unified theory of physics. Despite enormous progress in cosmology and particle physics, we still ...

Interstellar comet 3I/ATLAS and its unusual gas-to-dust chemistry Crewed and robotic lunar missions advancing sustained exploration Asteroid characterization and deflection studies supporting ...