Expect the unexpected: Interstellar object sparks speculation
A super-rare visitor from deep space—comet 3I/ATLAS—has just been spotted cruising through our solar system.
Astronomers in Chile caught it on July 1, 2025, and it's only the third confirmed interstellar object ever seen here.
This cosmic traveler is zipping along at a speedy 61km/s, coming from way outside the Sun's reach.
Comet to swing closest to Sun on October 29
Scientists aren't sure of its exact size yet, but it's probably less than 24km wide.
As sunlight hits it, the comet forms a faint glowing coma from its icy surface.
It'll swing closest to the Sun on October 29 (just inside Mars's orbit), and pass nearest to Earth in December—though still at a safe distance.
Over 7 billion years old!
3I/ATLAS is thought to be over seven billion years old and may have formed around an ancient star far across the galaxy.
With several months to observe it as it brightens, researchers hope this rare guest will reveal clues about how interstellar comets form and what they can tell us about other planetary systems.