The Current

Scientist argues Planet 9 should actually be Planet 11

Evidence of a new super planet in our solar system, Planet Nine, has its skeptics. Some scientists say the planet should be called Planet 10 because Pluto should never have been dropped a decade ago, and others also say the definition of what makes a planet was ill-conceived and fuzzy.

Astronomer explains his Planet 9 theory

6 years ago
Caltech researcher talks about the impact of his discovery 1:02
Scientists Konstantin Batygin and Mike Brown show that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration. The diagram was created using WorldWide Telescope. (R. Hurt/IPAC/Caltech)

This week, researchers may have discovered an as-yet undiscovered planet right in our very own solar system. It's being called Planet 9, and though Konstantin Batygin, professor of planetary science at The California Institute of Technology and colleague Mike Brown, have yet to actually see it, they say they have strong evidence that it must exist. 

(Tune into Quirks & Quarks this Saturday to hear our interview with Mike Brown, the man who both killed Pluto and has now proposed the existence of Planet 9.)

Batygin and Brown, both, led the charge to kill Pluto's planetary status a decade ago. But not everyone agrees that was the right decision.  

Tim DeBenedictis, currently works as an astronomy educational software developer. He believes Pluto is a planet and Eris should be included too.

​A moment of silence, for Pluto, if you please...

The distant orb known as Pluto was long considered the ninth planet in our solar system, until its demotion, in 2006, to dwarf-planet status. Planet Song for Kids sums up Pluto's demotion from "planet status":  


10 questions about the mighty dwarf planet Pluto

How well do you know the tiny planet? Take the CBC quiz and find out.


This segment was produced by The Current's John Chipman and Marc Apollonio.