Basic and Unexpected Discoveries about Movements of Lunar Dust: Implications from Revisiting Apollo Dust Detector Experiment Data

Recent analyses of measurements in 1969-70 by matchbox-sized Apollo Dust Detector Experiments (DDE) reveal a suite of basic characteristics of movements and stickyness of lunar dust neither foreseen nor incorporated in any 21st century theoretical models, nor in any strategies for planned lunar missions. For example, rocket exhaust gases caused expected dust contamination and overheating of Apollo 11 DDE deployed 17 meters from the Lunar Module (LM),but Apollo 12 caused unexpected and un-modelled cleansing of collateral dust from a DDE deployed 130m. Thus for either near or far deployment distance, astronaut photographs of dust on lunar experiments in every Apollo mission cannot be a reliable record of their condition after astronauts departed. Models for future lunar stations commonly assume that dozens of landings and liftoffs will add equal new contamination upon every previous contamination. Yet DDE measurements at Apollo 12 LM ascent are consistent with both (a) astronaut observations and photos at LM descent and (b) analyses of Surveyor 3 samples, only if LM descent winnowed potentially mobile dust away from the site. Consequently successive rocket exhausts at a future lunar station may not cause successive equal additive layers of contamination by dust.We have found no theoretical model which examines lunar dust adhesion to horizontal vis a vis vertical surfaces. Yet adhesive forces which caused troublesome dust to stick to any surface of Apollo hardware are now unexpectedly found to vary as solar elevation angle varies, being more sticky as solar illumination of a surface increases. To our knowledge, neither models of a lunar exosphere of levitated dust nor the factors favouring a settlement in a polar area rather than at a low latitude as with Apollo, has yet taken into account such basic but complex factors of variable adhesive forces. We also present Apollo 12 DDE data suggestive of levitated dust when the solar disc is about 1 degree above the Eastern horizon. We suggest it is prudent to examine current planning of some future lunar missions and experiments to examine if such new and fundamental information affects some models of dust movements which they may be narrowly designed to investigate. The situation provides a case study of a minimalist experiment belatedly illuminating theoretical physics in which basic assumptions may still be latent,neither articulated nor imagined, but exotic conclusions may have been made.