The interstellar comet 3I/ATLAS has just done something no visitor from another star system has ever been caught doing: it lit up in X-rays. As its elongated orbit carries it through the inner solar ...

Our solar system's famous "invader" might be as old as the Milky Way itself.

Add Yahoo as a preferred source to see more of our stories on Google. Remember 3I/ATLAS? Yes, the interstellar comet that made plenty of headlines in 2025 is still romping through our solar system.

Comets are pristine remnants left over from the solar system's formation 4.6 billion years ago, rather than younger fragments created by collisions between larger bodies, a new study suggests. The ...

New evidence suggests that the famous interstellar traveler may be so old that its home system no longer exists.

The comet originated in the outer solar system and visits the inner solar system every 5.4 years.

A mysterious interstellar comet — just the third such object ever confirmed to have entered our solar system — streaked past Mars last week. A spacecraft in orbit around the red planet had a front-row ...

Remember 3I/ATLAS? Yes, the interstellar comet that made plenty of headlines in 2025 is still romping through our solar system. But it may not be around much longer. The otherworldly visitor to ...