WASHINGTON (Reuters) - Dwarf planet Eris, similar in size to its better-known cosmic cousin Pluto, has remained an enigma since being discovered in 2005 lurking in the solar system's far reaches.

While both planets would likely be locked into a synchronous orbit -- with a permanent dayside and a perpetual nightside -- the ultrafast white dwarf planet's rotation stretches out the cloud ...

Astronomers have discovered an Earth-size planet orbiting an ultracool red dwarf star similar in size to Jupiter. The red dwarf, located some 55 light-years away, is 100 times less bright than the sun ...

WASHINGTON, May 30 (Reuters) - 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 ...

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 ...

Dwarf planet Ceres now appears less like a dead rock and more like a world that may have briefly brimmed with potential for life Ceres, the largest object in the asteroid belt between Mars and Jupiter ...