Astronomical constants and planetary ephemerides deduced from radar and optical observations
Abstract
A number of astronomical constants have been deduced by processing planetary radar data spannng the interval from 1959 to July 1966 and U. S. Naval Observatory optical data extending from 1950 to 1965. Results obtained using general relativity [Newtonian] theory with their formal standard errors are: a.u., 499.004786[499.004785]i0.000005 light sec; Mercury radius, 2434[2440]+2 km Venus radius, 6056[6056] 1 km; Mercury mass, 6021000[6029000]+53000; Venus mass, 408250[408450] 120; earth plus moon mass, 328900[328950]+6O; Mars mass, 3111000[3107000] 9000; earthmoon mass ratio 81.3030 [81.3024] 0.005. The planetary masses are given as inverses in terms of the solar mass. Corresponding mass density ratios are 0.9528[0.9527] 0.0008 for Venus/earth and 0.995[0.986] 0.009 for Mercury/earth. The orbital elements of Mercury, Venus, and the earthmoon barycenter were obtained simultaneously and the accompanying formal standard errors are substantially lower than heretofore achieved. The overall goodnessoffit measure 1N  E( )i/ffi]2 Ni1 was 0.63 for general relativity theory and 0.65 for Newtonian theory. Only for the fraction of data com prising timedelay observations of Mercury was a significant difference between the two theories noted; for this fraction general relativity gave E =0.7 and Newtonian theory 1.3.
 Publication:

The Astronomical Journal
 Pub Date:
 April 1967
 DOI:
 10.1086/110230
 Bibcode:
 1967AJ.....72..338A