Interstellar comet 3I/ATLAS makes closest approach to Earth on Thursday
Interstellar comet 3I/ATLAS, spotted in July 2025 by Chile's ATLAS survey, is making its closest pass to the Sun on October 30.
It's only the third interstellar object ever seen visiting our solar system, and its exact size is still unknown, but astronomers are studying its properties as it passes through the solar system.
No danger of collision with Earth
3I/ATLAS will swing inside Mars's orbit but never gets closer than about 270 million kilometers from Earth, so there's no danger here.
After October 30, catching a glimpse will be tough because of daytime glare and distance.
Comet shot out a dramatic fan of gas and dust
The comet shot out a dramatic fan of gas and dust as it neared the Sun—a classic move for icy space travelers.
Telescopes worldwide (including NASA's Hubble and James Webb) are tracking it closely since this rare visitor gives us a peek at material from another star system before it fades away into deep space.