These facts about the planets and the Moon were taken from two sources: JPL's HORIZONS ephemeris generator and the National Space Science Data Center's planetary fact sheets, which are probably based on the HORIZONS data. Diameters for the giant planets are at the 1-bar altitude. Orbital distances for the Moon are measured relative to Earth's center.
Become a member of The Planetary Society and together we will create the future of space exploration.
Our Advocacy Program provides each Society member a voice in the process. Funding is crucial.