title: Discrepancies between Radar Data and the Lunar Ephemeris.
abstract: Precise measurements of the Doppler shift of radar waves reflected from Moon disclose unexpectedly large discrepancies-averaging about 0.6 centimeter per second-between the radial velocities and the predictions based on the Eckert-Brown lunar ephemeris. These residuals have a rapidly changing component corresponding to a relatively large, variable, and unexplained discrepancy in radial acceleration of about 10(-4) centimeter per second, per second, in magnitude and about 1 day in period.
authors.forename: C R
authors.initials: CR
authors.lastname: Smith
authors.forename: G H
authors.initials: GH
authors.lastname: Pettengill
authors.forename: I I
authors.initials: II
authors.lastname: Shapiro
authors.forename: F S
authors.initials: FS
authors.lastname: Weinstein