Material around Chiron, a small icy world in the far reaches of the solar system, may be taking shape into a ring system of ...

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

Astronomers have found signs that the small icy world Chiron, orbiting between Saturn and Uranus, may be forming a new ring ...

Astronomers have been actively hunting for a ninth planet in the solar system ... between 100 and 200 times farther from the ...

Our solar system now, once again, officially consists of only eight planets. Although largely debunked, speculation continued ...

This long-duration comet will make its closest approach to Earth this fall, before disappearing into the outer solar system ...

As mankind was planning the first moon landing in the 1960s, an asteroid approached Earth—and still hasn’t left.

Comet 3I/ATLAS is warming up as it approaches the sun, causing a jet to emerge. The jet is visible in a dramatic new image.

The mysterious interstellar comet 3I/ATLAS is absolutely blasting out water at a staggering rate, astronomers found.

The European Space Agency also hoped to observe the interstellar object during its close approach to Mars using two ...

In a matter of days, Comet 3I/ATLAS will reach its closest point to the Sun. The third known interstellar object will reach ...

Observing 3I/ATLAS in this active phase will give some of the clearest insights yet into the mystery of interstellar comets.