alleryStart learning →The dark, smooth patches early observers called seas on the Moon are made of what?
AGranite from old crust
BBasalt from volcanic lava
CIce left by old comets
DDust blown by the wind
Answer & Solution
Correct answer: B. Basalt from volcanic lava
1. The dark patches were named maria, the Latin word for seas, by early observers.
2. They are not water but flat plains of dark basalt.
3. That basalt was erupted as lava that flooded huge impact basins long ago.
_Source: OpenStax Astronomy (CC BY 4.0), section 9.2 The Lunar Surface_
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