Highlights from a cometary trio that captured our imaginations.
3I/ATLAS has now made its closest approach to the sun and Earth and is now heading back out toward the outer solar system.
For one, it came down to timing.
A rare interstellar comet has been caught in X-rays by two space telescopes, revealing how its gases interact with charged particles from the sun as it travels through the inner solar system.
NASA JPL pinpoints the moment the interstellar visitor passes closest to our planet.
The livestream will now begin Friday at 11 p.m. EST, Dec. 19 (0400 GMT on Dec. 20), weather permitting, after rain prevented a broadcast on Thursday night.
Friday, Dec. 19, 2025: Your daily feed for the holiday flyby of interstellar comet 3I/ATLAS by Earth.
Dr. Larry Denneau of the University of Hawaii is nothing like your typical astronomer.
The direction, distance and motion of the comet through the sky during its closest approach could have made it seem like it was hovering over Bethlehem when Jesus was said to have been born.
The interstellar comet will pass safely by Earth, giving astronomers their best chance to study it up close.