Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

Full Video- http://www.youtube.com/watch?v=WHNO079G1i8 Pluto, Eris, and the Dwarf Planets of the Outer Solar System Exploring Space Lecture webcast live on Tuesday ...

WASHINGTON (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 it as it ...

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 ...

For More Webcasts: http://www.nasm.si.edu/webcasts/archive.cfm?siref=YouTube&video=PlutoErisDwarfPlanets Pluto, Eris, and the Dwarf Planets of the Outer Solar System ...