How did we miss a world 600 km wide?

References

1. 1
   Holman, Jurić, Napier et al., "2026 ED138: A Large Trans-Neptunian Object in Early Rubin Observatory Data, and How Many More May Remain", arXiv:2610.38693, submitted 28 October 2026

   arxiv.org

2. 2
   NSF–DOE Vera C. Rubin Observatory / NSF NOIRLab, "NSF–DOE Vera C. Rubin Observatory Reveals Its First Dwarf Planet Candidate in Our Solar System", noirlab2626, 27 October 2026

   noirlab.edu

3. 3
   IAU Minor Planet Center, MPEC 2026-U85, issued 27 October 2026

   minorplanetcenter.net

4. 4
   Emily Lakdawalla, "Possible New Dwarf Planet in the Solar System", Sky & Telescope, 30 October 2026

   skyandtelescope.org

5. 5
   Lisa Grossman, "This Halloween, amateur astronomers may be in for a dwarf planet treat", Science News, 30 October 2026

   sciencenews.org

6. 6
   Diameters of the five recognised dwarf planets: NASA Science fact pages for Pluto, Ceres, Eris, Haumea and Makemake

   science.nasa.gov

7. 7
   Images: NSF–DOE Vera C. Rubin Observatory/NOIRLab/SLAC/AURA (noirlab2626e, noirlab2626b), cropped; R. Proctor for the orbit render

   noirlab.edu