Our solar system is much like a trail of microcosmic breadcrumbs: Follow the molecular bits as far back as they go, and you'll learn a thing or two about where many of our planets and other celestial ...

In 2006, the International Astronomical Union (IAU) voted on the definition of a planet. Famously, Pluto no longer met the criteria and was demoted to a dwarf planet. Things have been a bit of a mess ...

The researchers said 2017 OF201 was identified in observations by telescopes in Chile and Hawaii spanning seven years. Scientists have identified an object about 435 miles (700 km) wide inhabiting the ...

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

New observations reveal that the far-flung object 2014 UZ224 (informally known as DeeDee, for "Distant Dwarf") is about 395 miles (635 kilometers) wide — big enough to claim "dwarf planet" status.

More than 50 times further from the Sun than Earth, the tiny dwarf planet Makemake is one of the last places you'd expect to find an intact gaseous atmosphere. Not only is it incredibly cold, being ...

Pluto, discovered in 1930, was once considered the ninth planet in our solar system. In 2006, the International Astronomical Union reclassified Pluto as a dwarf planet because it doesn't meet all the ...

A color-enhanced view of Ceres, the nearest dwarf planet to Earth, high­lights its Oc­ca­tor crater. Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA Pluto is the most famous dwarf planet, due in ...

WASHINGTON >> Scientists have identified an object about 435 miles wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a ...