Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
At 1:52 PM -0700 9/3/99, David Roberts wrote:
In pre-Sputnik 1955, C.W. Allen in his _Astrophysical Quantities _ gave
masses for the moon, the four Galilean satellites of Jupiter and 15 of the
larger satellites of the outer planets to 2 or 3 sig. fig. In all cases,
wobbles of the primary planet, due to the orbiting satellite, could be
observed.
Msun / Mp
Merc 6023600
Ven 408525.1
Earth 332946.043
Earth + Moon 328900.555
Mars 3098710
Jup 1047.3492
Sat 3497.91
Uran 22902.94
Nep 19434
Pl 13 x 10 e 7
Lang attributes these to J. Myles Standish, Jr. (1988) at JPL. The large
number of sig. fig. quoted reflect the fact that these values depend on
the hundreds or thousands of position and time measurements needed to
establish accurate values of the orbital elements.
By 1988 all the planets had been visited by spacecraft which made
very accurate mass determinations possible by doppler measurements.
Of course the results of such measurements could be most accurately
expressed in terms of a mass ratio, and the Sun's mass is standard.
I believe that all of them are thought to be more accurate than the
sort of analysis of conventional positional astronomy you suggest,
but I would have to check the literature. My Lang is at home, and
I probably don't have the journal in question (likely Icarus - lost
in our library's budget cutting in 1985) at hand, but I would be
glad to follow it up (in the fullness of time) if you haven't found
it there at Bowdoin by then.