Two weeks ago, interstellar comet 3I/ATLAS was at conjunction, on the opposite side of the Sun with respect to Earth. Last week, it reached perihelion, the closest point it would ever get to the Sun.

A strong solar flare peaked just after 9 a.m. Tuesday. What does that mean?

The Sun has never looked quite like this. With a quartet of small satellites flying in formation, NASA’s PUNCH mission is stitching together a seamless, cinematic view of solar eruptions as they leave ...

On January 22, 2026, interstellar comet 3I/ATLAS will align itself to within an exceptionally small angle with the Earth-Sun axis. At this alignment, the comet will allow the measurement of a novel ...