A newly discovered cluster of objects called the “inner kernel” of the Kuiper belt could teach us about the early history of the solar system – including the movement of Neptune

Earlier this summer, astronomers discovered something strange whizzing past Jupiter: an interstellar object. Scientists named it 3I/ATLAS. It’s only the third interstellar object ever observed, and it’s due to leave the solar system by the end of the ...

Object 3I/ATLAS is now too far from Earth to aim a telescope at, but prior observations showed some unusual behavior. The anomalous nature of the object led astrophysicist Avi Loeb to apply a thought experiment to it, highlighting everything about it that ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of Earth’s mantle and ejecting a huge debris disk that later formed the moon. Scientists have long wondered what Theia was made of and where it came from. Now they have evidence that it formed very close to home.

Big questions about 3I/ATLAS remain, some of which may be impossible to answer — including where exactly it came from Big questions about 3I/ATLAS remain, some of which may be impossible to answer — including where exactly it came from Big questions ...