Interstellar comet 3I/ATLAS to swing by Earth this December
Interstellar comet 3I/ATLAS will make its closest approach to Earth on December 19, 2025, cruising by at about 270 million kilometers away.
No worries—it's safely on the Sun's far side and won't pose any threat.
The comet zipped past its closest point to the Sun in October and is now heading out of our solar neighborhood.
How to spot it (if you're up for a challenge)
You won't catch 3I/ATLAS with just your eyes—it's faint, so you'll need a telescope with at least an eight-inch aperture.
Look for it during the eastern predawn hours this month.
For some extra help, NASA's Eyes on the Solar System app can track its position.
What makes this comet special?
Even though it has some quirky features, space telescopes like Hubble and JWST confirm it's a natural comet.
In late November, Japan's XRISM satellite picked up faint X-rays coming from around its nucleus—a cool effect caused by interactions between gasses from the comet and solar wind, something scientists often see in active comets.