value unc_up unc_lo author ref method 1.2100e+18 nan nan Folkner 2014IPNPR.196C...1F Ephem 3.2700e+18 5.8300e+17 5.8300e+17 Fienga 2011CeMDA.111..363F Ephem 7.6522e+17 3.5975e+17 3.5975e+17 Fienga INPOP19a Ephem