== Back To The Moon == === The Next Giant Leap for Humankind === === 2022 Joseph Silk / 629.454 SIL === . [[ https://en.wikipedia.org/wiki/Joseph_Silk | Joseph Ivor Silk Wikipedia ]] . astrophysicist and cosmologist . 1942, taught astronomy at UCB from 1970 to 1999, chair in 1978 . Papers about Moon . farside astronomy I was unable to finish this book. Too many mistakes and conjectures. References but few direct citations. No index. .p33 "The buried layers lying '''deep under''' the lunar surface must contain huge amounts of asteroid debris" . ''what evidence do we use to find them, and how do we access them?'' .p34 "The lunar surface is likely to be a unique site for mining rare earth elements" . cite 7 is not support for this claim, but a list of rare earth elements :-( .p35 "Based on analysis of the Apollo lunar samples, lunar reserves of rare earth elements approach a trillion tonnes - or 10,000 times more than the terrestrial reserves" ''no citation for this claim'' .p245 Ch1 note 10 "Optimal sites for optical and infrared telescopes are in the shadowed basins of polar craters, many of which are in permanent shadows. ... One could build 100-meter-class telescopes in such locations, far exceeding the aperture of any terrestrial rivals. ''uh, using how many kilotonnes of hardware and equipment, delivered how?'' .p245 Ch1 note 11 "Analogous features to the giant lunar lava tubes are found on Earth, but at much smaller scale" ''yes, and they fill with debris centuries after the eruptions that made them. Lunar volcanic eruptions are [[ https://www.science.org/content/article/recent-volcanic-eruptions-moon | more than 10 million years old ]], and nearly all of them are more than a billion years old.'' .The Apollo retroreflectors were covered with 90% opaque dust in half a century, are 1% transmissive now. What will happen to optical and microwave surfaces on the Moon? What happens to noise figure for a "resistive surface" microwave dish? .p275 Bibliography . [[ https://www.sciencedirect.com/science/article/abs/pii/S0019103512004174 | Persistently illuminated regions at the lunar poles: Ideal sites for future exploration ]] Emerson J. Speyerer, Mark S. Robinson, Icarus Volume 222, Issue 1, January 2013, Pages 122-136 . The Lunar Reconnaissance Orbiter Camera (LROC) provides multi-temporal and high resolution imaging of the north and south polar regions. These images delimit illuminated areas from those in shadow, and are used to analyze the illumination environment of the polar regions over the course of a lunar year. The Wide Angle Camera (WAC) provides repeat imaging of the north and south pole at a frequency of roughly 2 h with a ground sampling distance of 100 m. The LROC Narrow Angle Camera (NAC) acquires images with a ground sampling distance of 0.5-2.0 m providing the means to construct high resolution maps that reveal illuminated terrain under varying lighting conditions. With the multi-temporal coverage provided by the WAC and the high resolution images from the NAC, the LROC dataset enables a more comprehensive analysis of the illumination conditions near the lunar poles than any previous image based dataset. Furthermore, these images are used to validate previously published numerical models that simulate polar illumination conditions. From our analysis of the LROC images, we identified localized regions where the lunar surface remains illuminated for nearly 94% of the year with the longest eclipsed period lasting only 43 h. We also identified small illuminated peaks (tens of meters across) in areas previously modeled to be in shadow. Together, the WAC and NAC dataset provide direct, high resolution observations of the actual surface illumination environment of potential exploration sites near the lunar poles. .p277 https://www.nytimes.com/2019/07/12/science/nasa-moon-apollo-artemis.html .p278 [[ https://doi.org/10.1016/j.asr.2020.04.001 | Lunar and off Earth resource drivers, estimations and the development conundrum / Donald C. Barker ]] [[ https://www.researchgate.net/profile/Donald-Barker-2/publication/340671521_Lunar_and_Off_Earth_Resource_Drivers_Estimations_and_the_Development_Conundrum/links/5eb758754585152169c13292/Lunar-and-Off-Earth-Resource-Drivers-Estimations-and-the-Development-Conundrum.pdf ]] .p280 https://www.sciencealert.com/the-moon-s-biggest-crater-is-revealing-lunar-ancient-formation-history . South Pole-Aitken basin, thorium splash from index . https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JE006589 . Evidence for a Stratified Upper Mantle Preserved Within the South Pole-Aitken Basin . 18 December 2020 free access . 4.1.1 thorium "hotspots" up to ~6 ppm Th, "warmspots" > 3ppm, larger areas < 2.5 ppm .p280 Water and Other Volatiles on the Moon: A Review . A. T. Basilevsky, A. M. Abdrakhimov, and V. A. Dorofeeva . Solar System Research 2012, translated from Russian . https://www.researchgate.net/profile/Albert-Abdrakhimov/publication/257846141_Water_and_other_volatiles_on_the_moon_A_review/links/5851376e08aef7d0309cf959/Water-and-other-volatiles-on-the-moon-A-review.pdf .p280 https://ui.adsabs.harvard.edu/abs/2019AcAau.160..116S . Principles for a practical Moon base . Brent Sherwood, Acta Astronautica, Volume 160, p. 116-124, July 2019 .p285 . The G Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies III. The Reddest Extended Sources in WISE . Roger L. Griffith, Jason T. Wright, Jessica Maldonado, Matthew S. Povich, Steinn Sigurđsson, and Brendan Mullan . 2015 April 15 The Astrophysical Journal Supplement Series, Volume 217, Number 2 . DOI 10.1088/0067-0049/217/2/25 . https://iopscience.iop.org/article/10.1088/0067-0049/217/2/25/meta . [[ https://iopscience.iop.org/article/10.1088/0067-0049/217/2/25/pdf || PDF ]]