Related Experiment Video
Updated: Jul 5, 2026

Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
Neodymium isotope evidence for a chondritic composition of the Moon
K Rankenburg1, A D Brandon, C R Neal
1NASA Johnson Space Center, Mail Code KR, Houston, TX 77058, USA. kai.rankenburg1@jsc.nasa.gov
Abstract:
Samarium-neodymium isotope data for six lunar basalts show that the bulk Moon has a 142Nd/144Nd ratio that is indistinguishable from that of chondritic meteorites but is 20 parts per million less than most samples from Earth. The Sm/Nd formation interval of the lunar mantle from these data is 215(-21)(+23) million years after the onset of solar system condensation. Because both Earth and the Moon likely formed in the same region of the solar nebula, Earth should also have a chondritic bulk composition. In order to mass balance the Nd budget, these constraints require that a complementary reservoir with a lower 142Nd/144Nd value resides in Earth's mantle.
Related Concept Videos
Gravity between Spherical Bodies
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
Circular Orbits and Critical Velocity for Satellites
Nicolaus Copernicus (1473-1543) first suggested that the Earth and all other planets orbit the Sun in...
Gravitation
Gravitation Between Spherically Symmetric Masses
Reduced Mass Coordinates: Isolated Two-body Problem
Trigonometric Substitution

