Geology Reference
In-Depth Information
A15
A17
A11
A12
A14
A16
Nearside
Farside
Figure 6.1.
The nearside and farside of the Moon as captured by the wide angle camera on the
Lunar Reconnaissance Orbiter
mission. Compare with the terranes map of Figure 6.2. The dark, circular maria are prominent on the nearside, where the locations
of the six
Apollo
landing sites are indicated. Images courtesy of NASA/GSFC/Arizona State University.
Nearside
Farside
Imbrium
15
PKT
>3.5 ppm Th
17
FHT
<1 ppm Th
11
12
14
16
FHT
SPA
Figure 6.2.
Schematic terrane map of the Moon after
Jolliff et al
. [2000]. The six
Apollo
landing sites were all near the center of
the nearside. The distance between
Apollo
12 (west) and
Apollo
17 (east) is 16% of the lunar circumference. Three of the missions
(12, 14, and 15) landed in the geochemically anomalous Procellarum KREEP Terrane (PKT), a region with high concentrations of
incompatible elements such as Th [
Lawrence et al
., 2000;
Jolliff et al
., 2000]. All pixels with >3.5 ppm Th in the Th map of
Lawrence
et al
. [2000] lie within the PKT boundary of
Jolliff et al
. [2000], as depicted here. The
Apollo
11, 12, 15, and 17 lunar modules
landed in areas resurfaced by mare basalt. Only
Apollo
16 landed in the Feldspathic Highlands Terrane (FHT) distant from a mare.
The South Pole-Aitken Terrane encompasses the giant and ancient South Pole-Aitken (SPA) basin on the farside.
