Back to today’s briefing

Story perspectives

Search for Hypothetical 'Planet Y' Beyond Neptune Begins

8/25/2025

34 4

Summary

Story summary

Astronomers suggest a hypothetical planet, "Planet Y," beyond Neptune, due to warped orbits of Kuiper belt objects.
Planet Y may be smaller than Earth but larger than Mercury, potentially affecting nearby orbits.
The Vera C. Rubin Observatory will conduct a survey to search for Planet Y and its influence.
While speculative, past discoveries indicate hidden worlds can alter our understanding of the solar system.

1 of 1

Story summary

Astronomers suggest a hypothetical planet, "Planet Y," beyond Neptune, due to warped orbits of Kuiper belt objects.
Planet Y may be smaller than Earth but larger than Mercury, potentially affecting nearby orbits.
The Vera C. Rubin Observatory will conduct a survey to search for Planet Y and its influence.
While speculative, past discoveries indicate hidden worlds can alter our understanding of the solar system.