This intriguing observation points to physical changes occurring as the visitor traverses our solar system. Understanding ...

Interstellar comet 3I/ATLAS has turned a routine solar system flyby into a natural physics experiment, with a wobbling jet and a tail that appears to point toward the Sun instead of away from it. As ...

A planet's year length depends on its distance from the Sun. Planets closer to the Sun have shorter years. A planet's rotation speed is unrelated to its year length. Planets' orbital speeds vary ...