The Moon
Anorthosite
Say it: uh-NOR-thuh-syte IPA: /əˈnɔrθəsaɪt/ noun
Anorthosite: An igneous rock composed mostly of plagioclase feldspar, a group of minerals common in planetary crusts.
Much of the Moon's pale highlands is rich in this rock. In the leading picture of the early Moon, feldspar crystals floated in a magma ocean and helped build a crust.
- Example
- The lunar sample's abundant pale feldspar identified it as anorthosite.
- Why astronomers use it
- It preserves evidence about the Moon's early melting and the formation of its crust.
- Tiny cosmic connection
- Anorthosite also occurs on Earth; a pale rock is not automatically a Moon rock.
Observatory The Moon
Where to check it
Written for Cool Moon Facts in its own words; the sources cover the same idea in more depth.