A Comparative Study of Time on Mars with Lunar and Terrestrial Clocks

Abstract As space exploration extends into cislunar space and further toward Mars, understanding the relativistic effects on clocks on Mars—particularly in relation to multibody gravitational influences—becomes increasingly important for accurate clock synchronization. This study estimates clock rates on Mars and compares them to those on the Moon and Earth. We find that, on average, clocks on Mars tick faster than those on the Earth’s geoid by 477 μ s day −1 , with a variation of 226 μ s day −1 over a Martian year. Additionally, there is an amplitude modulation of approximately 40 μ s day −1 over seven synodic cycles. We also introduce a formalism that includes the effects of solar tides on the Earth–Moon system for predicting clock rates on the Moon and Mars more accurately when compared to using only Keplerian orbit approximations. Our analysis quantifies the relativistic proper-time offsets among Martian, lunar, and terrestrial clocks, highlighting important implications for mission planning and the implementation of timekeeping systems on Mars.