Almost 20 years after Pluto was infamously downgraded from its status as a planet, scientists now believe they have ...

A potential new dwarf planet has been discovered in the outer reaches of the solar system, and its existence poses the ...

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

For years, the existence of a missing Planet 9 has been one of the predominate theories attempting to explain some of the eccentric orbits found in the outer Solar System. But so far, no such ...

A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study's School of Natural ...

"For the first time in over 150 years, there is solid evidence that the solar system's planetary census is incomplete." No observational evidence for Planet Nine has been found, although this is ...

Now, there’s no scientific reason we can’t have thousands of planets in the solar system, but cultural considerations are a different issue. An overabundance of planets would seem to dilute ...

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 highly ...

Astronomers have discovered a rare solar system with six planets moving ... and it has been very busy. It has found no less than 7,000 planet candidates; 500-plus of them are confirmed, and ...

If you were born in the last century you might have memorized that there were nine planets in our solar system, as heard in ... The answer for many of us is no. That's exactly his point.