3I/Atlas making closest approach to Earth this week

3I/ATLAS update: NASA unveils close-up pictures

The interstellar object 3I/ATLAS has piqued the curiosity of space enthusiasts around the globe, and NASA offered new images with more information Wednesday of what they say is a comet. LiveNOW’s Austin Westfall is speaking with Astronomy Professor Ken Gayley from the University of Iowa after NASA provided more images and details during a live event on Wednesday.

3I/ATLAS, an interstellar object identified by NASA as a comet, will swing by Earth in its closest approach this week. 

Scientists have been tracking the comet’s grand tour of our solar system since it was discovered in July. 

Here’s what to know about the comet, and the timeline of its journey: 

What is the 3I/ATLAS comet? 

Hubble captured this image of the interstellar comet 3I/ATLAS on July 21, 2025, when the comet was 277 million miles from Earth. Image: NASA, ESA, David Jewitt (UCLA); Image Processing: Joseph DePasquale (STScI)

Big picture view:

The object known as 3I/ATLAS was discovered this summer after it entered our solar system from elsewhere in the galaxy. It got its name because it is the third interstellar object known to have visited our solar system (3I), and because ATLAS was the telescope in Chile that discovered the object. 

What we know:

The interstellar object had been believed to be a comet — which NASA confirmed Wednesday, despite several internet theories about it being alien technology. 

What they're saying:

"This object is a comet. It looks and behaves like a comet, and all evidence points to it being a comet. But this one came from outside the solar system, which makes it fascinating, exciting, and scientifically very important," NASA associate administrator, Amit Kshatriya, said in November.  

"We love that the world wondered along with us" what it was, said Dr. Nicky Fox, the associate administrator with NASA Science. 

What we don't know:

The exact nature and make-up of 3I/ATLAS remains unclear. And it’s also not known where exactly it came from, though scientists believe it may have originated in a star system much older than ours. 

READ MORE: NASA 3I/ATLAS comet update: ‘It’s a window into another solar system’

Where is 3I/ATLAS?

Timeline:

The object was discovered on July 1, 2025, out near Jupiter. 

Earlier in October, the comet approached Mars and came within 18 million miles of the red planet. On Oct. 30, it was the closest it would ever be to the sun, NASA said. 

Presently:

Now, in December, the comet is swinging back and will be closest to Earth on Friday, Dec. 19 — though still about 167 million miles away. 

What's next:

Then it will head towards Jupiter, where it will pass that planet’s orbit in the spring of 2026. 

It will be the mid-2030s before it reaches interstellar space, never to return, said Paul Chodas, director of NASA’s Center for Near Earth Object Studies.

Can you see 3I/Atlas with a telescope?

Big picture view:

Yes, it is possible to see 3I/Atlas with ground-based telescopes, NASA said, now that it has re-appeared on the other side of the Sun and will be at its closest position near Earth. Stargazing apps can point you where to look. 

Meanwhile:

Various NASA instruments and science teams are all working in tandem to study and learn as much as we can from the comet.