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 ...

The object is about 700 kilometres wide and lies nearly three times farther from Earth than Neptune. Its highly elongated ...

Scientists hunting for the hypothetical Planet Nine have discovered a potential new dwarf planet, 2017 OF201, in the outer ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system ...

It is an evocative idea: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

Some astronomers say the strange, clustered orbits of icy rocks beyond Neptune indicate that something big is out there, ...

A new dwarf planet discovery in the outer solar system is challenging the long-standing theory of a hidden giant planet ...

A US-based trio hunting this elusive world has stumbled on what appears to be a new dwarf planet in the solar system's outer ...