Lunar Meteorites

Lunar meteorites are rocks that fall from space and originally came from the Moon's surface. When a large object traveling through space strikes the Moon, the impact energy shatters the surface rock. Some of the fragments are ejected with enough force to overcome the Moon's gravity. These fragments travel in orbit around the Sun for extended periods before eventually falling to Earth.

These rocks are used to study the Moon's surface in locations where sample collection has not been possible. For example, the Apollo missions and the Luna program collected samples from specific locations on the lunar surface, whereas meteorites can originate from any part of the Moon, including the far side that faces away from Earth.

Identification

Identification relies on comparison with lunar samples previously collected. The mineralogical composition, oxygen isotope ratios, and other chemical signatures are examined. Lunar rocks possess isotopic signatures that consistently differ from those of Earth and Mars rocks. They typically contain breccia—rock composed of angular fragments cemented together, indicating a history of multiple impact events.

Where they are found

Most lunar meteorites are found in the Sahara Desert and Oman, as well as in Antarctic ice. The reason is that dark rock is easy to spot against the light surface of sand or ice, and cold, dry climates slow weathering and natural erosion.

Scientific importance

Lunar meteorites help reconstruct the Moon's interior, the history of impacts in space, and changes to the lunar surface over billions of years. Because they come from unselected locations, they provide a broader picture than Apollo samples alone. They also have high commercial value, which has prompted significant trade and collection activity.