
Unlikely, but it could be a dwarf PLANET.
The Big Bang Theory Season 9, Episode 12

Greetings from PLANET Earth.
The Big Bang Theory Season 8, Episode 21

or thinks the moon is a PLANET.
The Big Bang Theory Season 5, Episode 21

Yes, assuming the hypothetical PLANET
has a mass greater than the Earth.
The Big Bang Theory Season 1, Episode 13

living on a PLANET populated
with nothing but chimps.
The Big Bang Theory Season 5, Episode 21