(66652) Borasisi Trans-Neptunian Object
Discovered on 8 September 1999 by Trujillo, C. A., Luu, J. X., Jewitt, D. C. at Mauna Kea.
Also named is (66652) I Pabu, discovered 2003 Apr. 23 by K. Noll, D. Stephens, W. Grundy and colleagues using the Hubble Space Telescope. Borasisi and Pabu are the mythical personifications of the sun and moon in the fictional cosmogony of Bokononism described in Kurt Vonnegut's novel Cat's Cradle: “Borasisi, the sun, held Pabu, the moon, in his arms and hoped that Pabu would bear him a fiery child. But poor Pabu gave birth to children that were cold, that did not burn... Then poor Pabu herself was cast away, and she went to live with her favorite child, which was Earth.”Naming citation (20070926/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Borasisi is today
Seen from above the solar system on 2026-10-14: Borasisi is 42.8 au from the Sun and 41.9 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 66652 |
| Provisional designation | 1999 RZ253 |
| Orbit class | Trans-Neptunian Object |
| Absolute magnitude (H) | 5.85 |
| Orbital period | 289 years |
| Semi-major axis | 43.7 au |
| Perihelion – aphelion | 40.0 – 47.4 au |
| Eccentricity | 0.0847 |
| Inclination | 0.564° |
| Closest distance between its orbit and Earth's (MOID) | 39.0 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.