The extinct short-lived nuclide 146Sm, synthesized in stellar events by the p-process, serves as both an astrophysical and geochemical chronometer through measurements of isotopic anomalies of its alpha-decay daughter 142Nd. Evidence of live 146Sm, quantitatively established for the early Solar System, constrains the time between p-process nucleosynthesis and condensation of the first solid materials. Samarium-146 is used also to date silicate mantle differentiation events in a number of planetary bodies, including Earth. We performed a new measurement of the 146Sm half-life and our result, t = 68\pm7 (1sigma) million year (Ma), is significantly shorter than the value currently used for 146Sm-142Nd chronology (103\pm5 Ma). We show here that the shorter 146Sm half-life value implies a higher initial Solar System ratio, (146Sm/144Sm)_0 = 0.0094\pm0.0005 (2sigma), than the recently derived value 0.0085\pm0.0007, or that used in most studies 0.008\pm0.001. Planetary differentiation processes dated by 146Sm-142Nd converge to a shorter time span, due to the combined effect of the new 146Sm half-life and (146Sm/144Sm)_0 values. The revised 142Nd age of the recently dated Lunar ferroan anorthosite (FAN) 60025, is in agreement with its 147Sm-143Nd age; their weighted average, 196\pm11 (2sigma) Ma after Solar System birth, is consistent with the 208.8\pm2.4 Ma Pb-Pb age and with the age derived here (170\pm15 Ma) from an isochron of Lunar rocks.