... Abstract Determine the state (position, velocity) of an orbiting body from a set of elliptic, hyperbolic, or parabolic orbital elements. ... The difference between this state and the state predicted by the nominal orbit at the same epoch can be computed as follows. conics_c ( elts, later, nominal ); vsubg_c ( nominal, state, 6, diff ); printf( "Perturbation in x, dx/dt = %f %f", diff[0], diff[3] ); printf( " y, dy/dt = %f %f", diff[1], diff[4] ); printf( " z, dz/dt = %f %f", diff[2], diff[5] ); . ...

... 70 · Winter 2007 www.astrosociety.org/uitc © 2007, Astronomical Society of the Pacific 390 Ashton Avenue, San Francisco, CA 94112 Hubble Observations of Ceres and Pluto: A Closer Look at the "Ugly Ducklings" of the Solar System by Max Mutchler Space Telescope Science Institute Introduction regret that my 4th Grade teacher, Mrs. Hadley, doesn't know that she provided me with the very first astronomy book that I ever read, because it had a profound impact on me. ... Planet count 7 6 7 11 12 13 8 9 9? ...