The Lunar Apatite Paradox

• DOI: 10.1126/science.1250398
• Publication Date: 2014-03-21T04:40:07Z
• Authors: J. W. Boyce; S. M. Tomlinson; F. M. McCubbin; J. P. Greenwood; A. H. Treiman
• Keywords: Extraterrestrial Environment; 13. Climate action; Apatites; Silicates; Water; Fluorine; Crystallization; Moon; 01 natural sciences; Hydrogen; 0105 earth and related environmental sciences

Wetted Apatite

The long-running story of the dry Moon was rewritten a few years ago when hydrogen-bearing glass spherules were discovered. The highest water contents are found in lunar apatite, at levels suspiciously comparable to the water content of Earth apatites.

Boyce et al.

(p. 400 , published online 20 March; see the Perspective by

Anand

) now show that the water content of lunar apatite is not a reliable indicator of the abundance of water in mare basalts. The existence of apatite with high water content is an almost inevitable consequence of the loss of tiny amounts of fluorine-rich apatite from a melt and replacement by hydrogen and is thus no indication of a “wet” Moon.