May 30, 2014

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Constant Companion

NASA images compiled by Ross Sackett
NASA images (top row) AS11-40-5963, AS12-49-7286, AS14-68-9453; (bottom row) AS15-82-11140, AS16-116-18689, AS17-142-21791

A rock hammer is the field geologist's constant companion. Used to expose fresh rock on a weathered outcrop, clean the walls of a trench, or split fossil-bearing layers in sandstone and shale, the multi-functional geologist's hammer even does duty around camp splitting firewood and digging latrines. Each team of Apollo astronauts brought a hammer to the moon. On Apollo 11 and 12 a light (0.9 kg) hammer was used mainly to drive core tubes into the resisting regolith. On the more extensive geological traverses of Apollos 14 through 17 they brought a heavier hammer to knock chips from boulders and model as a scale object in photographs. Though light in the hand in the moon's weak gravity, the heavier hammer's 1.3 kg mass still packed the wallop of a hefty 3 pound hand sledge. An oddity of the Apollo hammers is their chisel end: though the lunar sites visited had a decidedly "hard-rock" lithology of (mostly) basalt, the chisel pattern resembles the layer-splitting hammers favored by terrestrial sedimentary geologists. Attached to an extension handle the hammer's chisel end could double as a hoe to dig shallow trenches in the regolith; however, I cannot find any Apollo surface photos showing them ever used this way. At the close of the final Apollo EVA geologist-astronaut Harrison 'Jack' Schmitt threw the last Apollo rock hammer a distance of some 40 meters. How long will his record stand before it is broken in a future Lunar Olympics?

Ross Sackett

P.S. Not many Apollo geological hammers are on public display. If you know of any please share in the Comments section.

Related Links
Apollo lunar geological tools
Jack Schmitt's record-setting hammer throw: Where is the hammer?, (video) (no longer a companion)

Yesterday's LPOD: Welcome Back, Paolo!

Tomorrow's LPOD: M & M


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