A mysterious interstellar comet older than the Sun is exposing alien chemistry and rewriting astronomy as we know it.

Scientists studying 3I/ATLAS have detected unusually high levels of heavy water, indicating it formed in an extremely cold ...

While scientists moved quickly to calm fears, the episode continued to fuel debate well after the headlines faded. Now, an unexpected response from a US intelligence agency has added a new layer to a ...

A flying piece of cosmic rock or an alien threat? Comet 3I/ATLAS is hurtling through our solar system and captivating scientists and internet users alike. This NASA image shows the interstellar comet ...