Calculating the solar mass

planets={"Mercury","Venus","Earth","Mars",
"Jupiter", "Saturn","Uranus","Neptune"};

planetDistances=QuantityMagnitude[
UnitConvert[
PlanetData[planets,"AverageOrbitDistance"]]];

planetPeriods=QuantityMagnitude[
UnitConvert[
PlanetData[planets,"OrbitPeriod"]]];

G=QuantityMagnitude[
UnitConvert[Quantity["GravitationalConstant"]]];
v=2 Pi planetDistances/planetPeriods;
solarMasses=planetDistances v^2/G;

solarMass=QuantityMagnitude[
UnitConvert[Quantity["SolarMass"]]];

points=Transpose[
{Log10[planetDistances],solarMasses/solarMass}];
ListPlot[points,PlotRange->{{10.5,13.0},{0.99,1.07}},
AxesLabel->{"Log(Distance/m)","Calculated/True"},
PlotMarkers->{Automatic,Large}]