The image below compares the sizes of the largest outer solar system objects. It includes:

• the Earth, the Moon, and Mercury (the smallest planet other than Pluto), for reference;
• the three largest asteroids: (1) Ceres, (2) Pallas, and (4) Vesta;
• Triton, the largest satellite of Neptune;
• Pluto, its satellite Charon, and its two newly discovered smaller satellites;
• the newly discovered planet-sized object 2003 UB313 with its satellite
• the two other newly discovered large objects: 2003 EL61 (with its two satellites) and 2005 FY9;
• the distant object (90377) Sedna;
• the other known trans-Neptunian objects that are at least 650 km in diameter;
• a few other illustrative objects: (28978) Ixion and both components of the binary (47171) 1999 TC36.

Relative sizes, brightnesses, and colors are shown.

© 2005, 2006 by Wm. Robert Johnston.
Last modified 30 April 2006.
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