What is the Moon made of?
The Moon’s composition and internal structure are not known in great detail. Most of what we do know comes from studying samples of the lunar surface returned by Apollo missions and from seismic studies performed both remotely from Earth and by astronauts on the Moon. Rocks from the lunar surface are all igneous, having been created below the surface then carried to it by meteor impacts or by the Moon’s now-defunct volcanoes. They consist primarily of typical Earth minerals like olivine, feldspar, and quartz, though some minerals found are unique to the Moon — tranquillityite, armalcolite, and pyroxferroite. As for the Moon’s interior, our understanding of its structure is much more limited. Most scientists agree on the following general concepts: the remains of countless meteor impacts and volcanic flows dominate the first 60 miles below the surface; the next 60 to 100 miles of lunar “crust” is rich in metals. Deeper below the surface, the structure becomes less clear; starting about
