... Satellites of the planets are assigned a provisional designation (indicating year of discovery) by the Central Bureau for Astronomical Telegrams ( CBAT ) upon satisfactory demonstration of the existence of a new object. ... In the past, Comets were first given a provisional designation, consisting of the year and a lowercase letter indicating the order of discovery in the year (e.g., 1994a was the first comet discovered or recovered in 1994, 1994b the second, etc.) ... Names .. ...
Comets necessarily obey the same physical laws as every other object. ... If one considers only two bodies -- either the Sun and a planet, or the Sun and a comet -- the smaller body appears to follow an elliptical path or orbit about the Sun, which is at one focus of the ellipse. ... Another quantity that is conserved is called angular momentum. ... Comets simply are bodies which in general have more angular momentum per unit mass than do planets and therefore move in more elongated orbits. ...
... 9a. Earth orbits Sun? . ... 10a. Scale of Solar Sys. ... If the mean distance of Earth from the Sun is 1 AU ("Astronomical Unit"), then that of Venus is 0.723 AU, of Mercury 0.387 AU and that of Mars is 1.524 AU. ... By noting (1) where on the Sun's disk is the crossing seen, (2) timing its duration at two far-apart points on Earth, and (3) comparing the times, one can calculate the distance to Venus and from it the scale of the solar system. ... One occurred in 1639--too early. ...