New photos, including a striking technicolor timelapse, show off the newly discovered interstellar object 3I/ATLAS as it ...

This artist’s concept depicts one of the solar system’s inner planets slamming into Earth after being nudged on a collision course by a passing star. Such a world-shattering cataclysm is ...

This new dwarf planet may exist at the edge of the solar system, possibly disproving Planet Nine's existence. This is the story of that newly encountered planet.

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

Almost 20 years after Pluto was infamously downgraded from its status as a planet, scientists now believe they have discovered a new planet in our solar system.

Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a ...

Scientists may have found evidence of a ninth planet hiding out beyond Pluto, but is it actually Planet Nine?

A new study sheds light on what Jupiter, often called the "architect" of the solar system, was like in the beginning. The giant planet has dramatically changed.

This process, called accretion, is how everything in the solar system – planets, moons, comets and asteroids – came into being. Telescopes can see young solar systems being born.

Jupiter, The Largest Planet In Our Solar System, Was Once Twice As Big Even today, Jupiter dominates the other planets in size, and modeling suggests it was once larger still.

This "lost" planet could have been tossed into deep space during the early chaotic days of our solar system when massive planets were still shifting around.