The presence of deuterium, an isotope of hydrogen, in 3I/ATLAS suggests the interstellar comet formed in a much colder place ...

An interstellar comet carries water unlike anything in our solar system, revealing a far colder birthplace and clues about ...

Long before 3I/ATLAS slipped through the inner solar system, its water had already recorded the kind of place it came from.

Over the next two weeks stargazers have a chance to spot the blue-green orb and smudgy tail of comet known as C/2025 R3 PanSTARRS ...

A comet tearing through the inner solar system at roughly 58 kilometers per second formed between 10 and 12 billion years ago ...

ALMA reveals unusual “alien” water in interstellar comet 3I/ATLAS, showing it formed in an extremely cold, distant star ...

Learn more about the interstellar traveler, Comet 3I/ATLAS, and what researchers know about its place of origin.

The astronomer used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to make the observations.

Astronomers analyzed the vapors coming off the comet when it neared the sun and found it had a lot of "heavy" water. That ...

Measurements of this interstellar comet’s molecular makeup show an excess of heavy water molecules that is dramatically ...