204 forecasters

Will Planet Nine be Discovered by mid-2019?

29%chance

29%chance

ResolvedNo

ResolvedNo

The community gave this a 29% chance, and it resolved No.

Forecast Timeline

Authors:

Opened:

Jan 23, 2018

Closes:

Dec 31, 2018

Resolved:

Jul 1, 2019

Spot Scoring Time:

Jan 24, 2018

Natural Sciences

2018-2019 Leaderboard

Meet ‘Planet Y’ As New Evidence Suggests Secret World Beyond Neptune

Forbes•Sep 11, 2025

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