It is a question that feels like it should have a straightforward answer: how many planets are there in our solar system? Since Pluto was relegated back down to dwarf planet status, almost everyone ...

American astronomers have discovered a new dwarf planet at the edge of the solar system, which has already been named 2017 OF201. This object is known to have a huge orbit and a potential size, close ...

-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 ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

By combining the power of ground-based and space-based telescopes, astronomers have discovered a new brown dwarf—a type of ...