...exploring a PLANET similar to Earth
in the 1500s.
The Big Bang Theory Season 2, Episode 2
It could be a sign of an
extra-solar PLANET that may contain life
The Big Bang Theory Season 10, Episode 8
Right now Howard
is staring down at our PLANET...
The Big Bang Theory Season 6, Episode 1
Yes, assuming the hypothetical PLANET
has a mass greater than the Earth.
The Big Bang Theory Season 1, Episode 13
Daddy needs a livable PLANET
he can rule with an iron fist.
The Big Bang Theory Season 9, Episode 12