TY - JOUR
T1 - Lunar science
T2 - An overview
AU - Taylor, Stuart Ross
PY - 2005/12
Y1 - 2005/12
N2 - Before spacecraft exploration, facts about the Moon were restricted to information about the lunar orbit, angular momentum and density. Speculations about composition and origin were unconstrained. Naked eye and telescope observations revealed two major terrains, the old heavily cratered highlands and the younger mostly circular, lightly cratered maria. The lunar highlands were thought to be composed of granite or covered with volcanic ash-flows. The maria were thought to be sediments, or were full of dust, and possibly only a few million years old. A few perceptive observers such as Ralph Baldwin (Baldwin 1949) concluded that the maria were filled with volcanic lavas, but the absence of terrestrial-type central volcanoes like Hawaii was a puzzle. The large circular craters were particularly difficult to interpret. Some thought, even after the Apollo flights, that they were some analogue to terrestrial caldera (e.g., Green 1971), formed by explosive volcanic activity and that the central peaks were volcanoes. The fact that the craters were mostly circular was difficult to accommodate if they were due to meteorite impact, as meteorites would hit the Moon at all angles. The rilles were taken by many as definitive evidence that there was or had been, running water on the lunar surface. Others such as Carl Sagan thought that organic compounds were likely present (see Taylor 1975, p. 111, note 139).
AB - Before spacecraft exploration, facts about the Moon were restricted to information about the lunar orbit, angular momentum and density. Speculations about composition and origin were unconstrained. Naked eye and telescope observations revealed two major terrains, the old heavily cratered highlands and the younger mostly circular, lightly cratered maria. The lunar highlands were thought to be composed of granite or covered with volcanic ash-flows. The maria were thought to be sediments, or were full of dust, and possibly only a few million years old. A few perceptive observers such as Ralph Baldwin (Baldwin 1949) concluded that the maria were filled with volcanic lavas, but the absence of terrestrial-type central volcanoes like Hawaii was a puzzle. The large circular craters were particularly difficult to interpret. Some thought, even after the Apollo flights, that they were some analogue to terrestrial caldera (e.g., Green 1971), formed by explosive volcanic activity and that the central peaks were volcanoes. The fact that the craters were mostly circular was difficult to accommodate if they were due to meteorite impact, as meteorites would hit the Moon at all angles. The rilles were taken by many as definitive evidence that there was or had been, running water on the lunar surface. Others such as Carl Sagan thought that organic compounds were likely present (see Taylor 1975, p. 111, note 139).
KW - Chemical composition
KW - Late heavy bombardment
KW - Magma ocean
KW - Origin of Moon
UR - http://www.scopus.com/inward/record.url?scp=33747889341&partnerID=8YFLogxK
U2 - 10.1007/BF02715941
DO - 10.1007/BF02715941
M3 - Article
SN - 0253-4126
VL - 114
SP - 587
EP - 591
JO - Journal of Earth System Science
JF - Journal of Earth System Science
IS - 6
ER -