Rocky bodies called protoplanets were thought to have formed slightly earlier in the inner solar system than those beyond the ...

Officially named 3I/ATLAS, the comet was confirmed as having originated outside of Earth's solar system on July 3, according ...

A new investigation into old Kepler data has revealed that a planetary system once thought to house zero planets actually has ...

NASA has discovered an interstellar comet that's wandered into our backyard. The space agency spotted the object with the sky ...

Identifying the formation period of planetary systems, such as our solar system, could be the beginning of the journey to ...

How Many Planets Are There in the Solar System? There are 8 planets in our solar system. The planets orbit the Sun in elliptical trajectories, and they are all different in size, composition, ...

If there were one, that Planet Nine would "nudge the closest part of 2017 OF201's trajectory inward until Neptune flung it out of the solar system." Because 2017 OF201 is there, that could be an ...

For now, the outer reaches of our 4.6 billion-year-old solar system continue to be shrouded in mystery, with the classification of objects changing as scientists gain a new understanding of them ...

There could be a ninth planet in our Solar System after all — and no, it’s not Pluto. Instead, it’s the theoretical Planet X, also called Planet Nine, a wide-orbit planet that would circle the Sun ...

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

If this planet is still out there, it could be wandering somewhere far beyond our reach. So, was our solar system supposed to have one more planet? Looks like the universe had other plans!

The long-theorized Planet 9, which astronomers have speculated could be a Neptune-sized planet that has been lurking on the outer edge of the solar system, could explain the unusual clustering and ...