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Apollo 11

Apollo 11 Preliminary Science Report (NASA SP-214)

Summary

Section titled “Summary”

The first official scientific report on the Apollo 11 results, prepared shortly after the mission. Its ten chapters cover a photographic summary, the crew’s own observations, the geologic setting of the landing site (Shoemaker et al.), the soil mechanics of the regolith, the preliminary examination of the returned samples, and the deployed surface experiments — the EASEP (Passive Seismic and Laser Ranging Retroreflector, with a modified dust detector) plus the separately deployed Solar-Wind Composition foil. It is the foundational science reference for the mission, written before the multi-year detailed analyses that followed.

Key takeaways

Section titled “Key takeaways”
  • Returned material: about 22 kg of lunar material — roughly 11 kg of fragments larger than 1 cm and 11 kg smaller — divided into four types: A (fine-grained vesicular crystalline igneous rock), B (medium-grained crystalline igneous rock), C (breccia), and D (fines).
  • Crystalline rocks (20 found, 10 type A + 10 type B; up to 919 g): dominated by clinopyroxene and plagioclase with abundant opaque minerals (notably ilmenite), resembling terrestrial basalts but far richer in refractory elements (Ti, Zr, Y, Cr) and depleted in alkalis/volatiles and water.
  • Breccias and fines are shock products of the regolith; fines are ~50% glass with Ni-Fe spherules, indicating impact melting.
  • Regolith & soil mechanics: the site sits on a fragmental debris layer (regolith) ~5 m thick built by repeated impacts; bearing strength inferred from footprint and landing-gear penetration is low at the surface and rises with depth.
  • Ages: potassium-argon dating gives a crystallization age of ~3.0 ± 0.7 × 10⁹ yr (older than expected for the maria); cosmic-ray exposure ages range ~20–160 × 10⁶ yr. Rare-gas content in fines/breccias (~0.1 cc/g) is mostly implanted solar wind.
  • Experiments: the Passive Seismic Experiment, Laser Ranging Retroreflector, and Solar-Wind Composition experiment each returned usable data; the SWC foil confirmed solar-wind noble gases directly.
  • Sample-return scheme: a ~1 kg contingency sample, a bulk sample, a documented sample, and two core tubes filled the sample-return containers.

Concepts extracted

Section titled “Concepts extracted”