The Moon is fixed in its “mean Earth / polar axis” frame (latitude, east longitude 0 to 360°), that of LOLA and of the IAU names. The Sun, the Earth and the orbiters move around it. The JPL Horizons tables (DE441 ephemeris, every 30 minutes) give the sub-solar point, hence day and night and the terminator, and the sub-Earth point, i.e. the libration: the Moon always shows the same face but sways by a few degrees, so that 59 % of its surface can be seen from the Earth. The blue line marks the edge of the face turned to the Earth at this instant. The night side seen from the Earth receives earthshine, sunlight sent back by the Earth; it is the stronger the fuller the Earth seen from the Moon. Phase and age come from the formulae of Meeus (1998, ch. 49).
The catalogue of the Apollo seismic network covers 1969 to 1977, with the stations of missions 12, 14, 15 and 16 (Nakamura et al. 1981, 2005). It holds 13,058 events, of which 1,359 deep moonquakes grouped in nests 700 to 1,200 km deep. For each nest with at least 10 quakes, a Rayleigh test measures whether the dates cluster in three cycles: the anomalistic month (27.55 d, perigee to perigee) and the draconic month (27.21 d), which set the tide raised by the Earth, and the synodic month (29.53 d), that of the phases and of sunlight. Of the 28 nests tested, all 28 are set by the tidal months (p < 0.01) and a single one by the synodic month, as expected by chance. Deep moonquakes are therefore triggered by the Earth’s tide, not by the Sun’s heat (Lammlein 1977; Bulow et al. 2007).
A click on the ground gives the elevation of the 1/4° LOLA grid (Smith et al. 2010), the height of the Sun and the time until it rises or sets (a lunar day lasts 29.5 days). It also gives a daytime temperature estimated by radiative balance, T = [S(1 − A) cos z / (εσ)]^¼ with A = 0.12 and ε = 0.95, which gives 386 K at the sub-solar point, in line with the Diviner measurements (Vasavada et al. 2012), and the place of the Earth in the sky.
- Park et al. (2021)
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Park, R. S., Folkner, W. M., Williams, J. G., & Boggs, D. H. (2021). The JPL Planetary and Lunar Ephemerides DE440 and DE441. The Astronomical Journal, 161, 105. Tables: JPL Horizons (Giorgini et al. 1996).
· doi:10.3847/1538-3881/abd414
Licence : Published literature; cited - Smith et al. (2010)
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Smith, D. E., Zuber, M. T., Neumann, G. A., et al. (2010). Initial observations from the Lunar Orbiter Laser Altimeter (LOLA). Geophysical Research Letters, 37, L18204. Grid: LOLA LDEM 4 pixels per degree (PDS Geosciences Node); shaded relief: NASA Moon Trek.
· doi:10.1029/2010GL043751
Licence : Published literature; cited - Robinson et al. (2010)
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Robinson, M. S., Brylow, S. M., Tschimmel, M., et al. (2010). Lunar Reconnaissance Orbiter Camera (LROC) instrument overview. Space Science Reviews, 150, 81–124. Map: LROC WAC global mosaic, served by NASA Moon Trek.
· doi:10.1007/s11214-010-9634-2
Licence : Published literature; cited - Nakamura (2005)
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Nakamura, Y. (2005). Farside deep moonquakes and deep interior of the Moon. JGR Planets, 110, E01001. Catalogues: Nakamura, Y., et al. (1981), Passive seismic experiment long-period event catalog, UTIG; Nakamura, Y., et al. (1979), Shallow moonquakes, Proc. LPSC 10, 2299–2309 (PDS Geosciences Node).
· doi:10.1029/2004JE002332
Licence : Published literature; cited - Lammlein (1977)
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Lammlein, D. R. (1977). Lunar seismicity and tectonics. Physics of the Earth and Planetary Interiors, 14, 224–273.
· doi:10.1016/0031-9201(77)90175-3
Licence : Published literature; cited - Bulow et al. (2007)
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Bulow, R. C., Johnson, C. L., Bills, B. G., & Shearer, P. M. (2007). Temporal and spatial properties of some deep moonquake clusters. JGR Planets, 112, E09003.
· doi:10.1029/2006JE002847
Licence : Published literature; cited - Watters et al. (2019)
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Watters, T. R., Weber, R. C., Collins, G. C., et al. (2019). Shallow seismic activity and young thrust faults on the Moon. Nature Geoscience, 12, 411–417.
· doi:10.1038/s41561-019-0362-2
Licence : Published literature; cited - Vasavada et al. (2012)
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Vasavada, A. R., Bandfield, J. L., Greenhagen, B. T., et al. (2012). Lunar equatorial surface temperatures and regolith properties from the Diviner Lunar Radiometer Experiment. JGR Planets, 117, E00H18.
· doi:10.1029/2011JE003987
Licence : Published literature; cited - Gazetteer of Planetary Nomenclature, IAU Working Group for Planetary System Nomenclature, USGS Astrogeology Science Center.
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Gazetteer of Planetary Nomenclature, IAU Working Group for Planetary System Nomenclature, USGS Astrogeology Science Center.
Licence : Published literature; cited - Meeus (1998)
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Meeus, J. (1998). Astronomical Algorithms, 2nd ed., ch. 47–49: position and phases of the Moon. Willmann-Bell.
Licence : Published literature; cited