Films

Planet Nine: Is There Another Planet Beyond Neptune?

Published Oct 31, 2026 · 36 min

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In 1846, astronomers found Neptune by pointing a telescope where a calculation said a planet should be. In 2016, two Caltech astronomers argued that a pattern in the orbits of distant icy objects pointed to another unseen planet, far beyond Neptune. More than ten years later, nobody has found it.

Narration in this film is a synthetic, cloned voice. Sources and image credits are in the YouTube description.

Chapters

1. 00:00 A planet found by mathematics
2. 01:49 Beyond the familiar map
3. 03:24 The clues in distant orbits
4. 06:52 When the mathematics worked
5. 11:19 What the hypothetical planet would do
6. 14:31 Could the search create the pattern?
7. 18:09 New tests of the idea
8. 21:44 Why a planet could be hard to see
9. 25:11 What the searches have ruled out
10. 28:46 Rubin and the next chapter
11. 32:15 What would settle the question?

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