Uploaded September 2021 | Updated September 2026, 2 weeks ago

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There are eight known planets in the Solar System now that Pluto has been downgraded to a dwarf planet. But could there be a ninth planet, orbiting the Sun much further out?

My other YouTube channels:
The Science Fiction Rock Experience ( the music show I produce):
youtube.com/@ScienceFictionRockExperience
Discover Maths (with Juan Medina):
youtube.com/@discovermaths
Science World (with Emrah Polat):
youtube.com/@ScienceWorld1

My website: daviddarling.info

Music: purple-planet.com