Ashby, N.
and Patla, B.
(2025),
A comparative study of time on Mars with lunar and terrestrial clocks, The Astronomical Journal, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960410
(Accessed December 2, 2025)
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A comparative study of time on Mars with lunar and terrestrial clocks
Published
Author(s)
Neil Ashby,
Abstract
As space exploration extends into cislunar space and further towards Mars, understanding the relativistic effects on clocks on Mars—particularly in relation to multi-body 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$\mu\rms}\rmday}^-1}$, with a variation of 226$\mu\rms}\rmday}^-1}$ over a Martian year. Additionally, there is an amplitude modulation of approximately 40$\mu\rms}\rmday}^-1}$ over seven synodic cycles. We also introduce a formalism for addressing 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.Citation
The Astronomical Journal
Volume
171
Issue
1
Pub Type
Journals
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Created December 1, 2025