How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between ...

Experts have confirmed that the mysterious object hurtling towards us, previously dubbed A11pl3Z, is an "interstellar object.

NASA has discovered a new interstellar comet that's currently located about 420 million miles away from Earth. The space ...

Don't worry though—it's not like one planet simply fell out of the solar system. We'll explain what happened and also show you some tricks for remembering the order of all of the planets that ...

A fascinating glimpse into how a solar system like our own is born has been revealed with the detection of planet-forming ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system. The object—which orbits out beyond Neptune—has been named "2017 OF201" by the ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory ...

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.

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 ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to ...