Every few years, something slips through our cosmic neighborhood that doesn't belong here. It arrives from somewhere out past ...

Exactly where the comet 3I/ATLAS came from within the Milky Way remains a mystery.

Eventually, we'll launch a mission dedicated solely to studying an interstellar object. When that day comes, which one should ...

For almost a decade—ever since 2017, when our first known interstellar visitor, 1I/‘Oumuamua, swooped through the inner solar ...

Comet 3I/ATLAS arrived from beyond the Solar System carrying a chemical story unlike anything astronomers had measured before ...

Astronomers have used the European Southern Observatory's Very Large Telescope (ESO's VLT) to study the composition of ...

Based on the composition of gases spewed by the icy space rock, researchers estimate that our guest might be up to 12 billion years old—about three times the age of the solar system ...

During last year’s brief visit from the comet 3I/ATLAS, astronomers got an extremely rare glimpse into the cosmos beyond our ...

Cropped image of NASA’s James Webb Space Telescope observation of comet 3I/ATLAS with its Near-Infrared Spectrograph ...

3I/ATLAS is surrounded by “a complex jet structure,” new images show, sparking fresh speculation that the Manhattan-sized interstellar object could be an artificial alien craft. The images, captured ...

In the latest research, telescope observations of 3I/ATLAS examine its chemical structure and suggest that it took shape in a ...