The first clue came from Pluto. The oddball of the solar system, it dips far above ... Because the planets were also tugging on one another, the whole system was fragile—“almost infinitely ...

When astronomers realized that Ceres had many "relatives" in roughly the same region of the solar system ... Pluto fans thought it was pretty cool to be the first and defining member of a whole ...

After passing Pluto, the craft will continue into the farthest reaches of the solar system. Scientists suspect there may be yet more moons around Pluto, some perhaps sharing or swapping orbits and ...

Almost 10 years ago, a NASA spacecraft was able to take several photos of Pluto, known for decades as a planet before it was ...

A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is ...

Pluto is back! His adventures searching for the mysterious dwarf planets continue! Welcome to SolarBalls! Space animation ...

And so the whole thing was kind of weird to start ... NASA said it’s the largest known glacier in our solar system. Images of Pluto’s icy heart have appeared on screensavers and T-shirts ...

The Sweden Solar System is the largest scale model of the Solar System in existence, and it spans the entire Swedish ...

Pluto (smaller sphere) and its moon Charon are the first guideposts of the Kuiper Belt. They may help reveal why planets long ago stopped forming in the outer solar system. Illustration by Ron ...

Pluto isn’t the only dwarf planet in our solar system's outer reaches. Now is an ideal time to look for the egg-shaped Haumea, says Abigail Beall ...

The sun accounts for 99.8% of the mass of the entire Solar System ... However, we actually have six in our Solar System. Pluto, Ceres, Makemake, Haumea, and Eris were the only five that we ...