Mars is fixed, in planetocentric coordinates (latitude, east longitude 0 to 360°, the IAU 2000 system used by MOLA). The Sun, the Earth, the moons and the orbiters move around it. The season (solar longitude Ls), Mars time and the sub-solar point, hence day and night, are computed at every instant with the algorithm of Allison and McEwen (2000) used by Mars24 (NASA GISS). Checked against JPL Horizons at three dates, the difference is 0.002° in Ls and in sub-solar longitude. Mars Years follow the convention of Clancy et al. (2000): year 1 begins on 11 April 1955.
The moons and orbiters are placed from JPL Horizons tables, which give every 2 to 15 minutes the point of Mars below them and their distance. These values are interpolated at the current instant; Phobos and Deimos follow the ephemerides of Jacobson (2010). The direction of the Earth is the apparent one seen from Mars, light travel time included. Rover positions are the localizations published by their teams. Names come from the IAU gazetteer, which lists 2,052 names on Mars; only the large ones are kept.
A click on the ground gives the elevation of the 1/4° MOLA grid (Smith et al. 2001). The pressure is estimated from the seasonal pressure curve measured by Curiosity, fitted over 14 years in the analysis “Seasons and pressure on Mars”, then scaled to the elevation of the point by hydrostatic balance, p = p₀ exp(−Δh / H) with H = 11.1 km. This estimate links three phenomena: the season, which condenses up to a quarter of the atmosphere onto the polar caps, the relief and the triple point of water. Independent check: the pressure drift measured by Curiosity matches a climb of about 980 m; its localizations give 1,013 m, from −4,501 m at landing to −3,488 m today.
- Allison et al. (2000)
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Licence : Published literature; cited - Clancy et al. (2000)
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Clancy, R. T., Sandor, B. J., Wolff, M. J., et al. (2000). An intercomparison of ground-based millimeter, MGS TES, and Viking atmospheric temperature measurements: Seasonal and interannual variability of temperatures and dust loading in the global Mars atmosphere. JGR Planets, 105(E4), 9553–9571.
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Licence : Published literature; cited - Smith et al. (2001)
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Licence : Published literature; cited - Gazetteer of Planetary Nomenclature, IAU Working Group for Planetary System Nomenclature, USGS Astrogeology Science Center.
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Martínez, G. M., Newman, C. N., De Vicente-Retortillo, A., et al. (2017). The modern near-surface Martian climate: a review of in-situ meteorological data from Viking to Curiosity. Space Science Reviews, 212, 295–338.
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Stähler, S. C., Khan, A., Banerdt, W. B., et al. (2021). Seismic detection of the martian core. Science, 373, 443–448.
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Black, B. A., & Mittal, T. (2015). The demise of Phobos and development of a Martian ring system. Nature Geoscience, 8, 913–917.
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Orosei, R., Lauro, S. E., Pettinelli, E., et al. (2018). Radar evidence of subglacial liquid water on Mars. Science, 361, 490–493.
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