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CBSE Class 9 Answered

moon has no atmoshphere?why
Asked by ujjwalviky2003 | 29 Oct, 2017, 10:26: PM
answered-by-expert Expert Answer
Atmosphere above earth surface consists of air. Since there is no air present above moon surface.
 
Another explanation related to escape velocity. 
Escape velocity is given by begin mathsize 12px style v space equals space square root of fraction numerator 2 G M over denominator R end fraction end root end style. Here M and R are mass and radius of earth/moon respectively.
For earth escape velocity is 11.2 km/s. 
But for moon escape velocity is 2.38 km/s.
Hence due to thermal energy all gases will escape from moon surface due to low escape velocity
Answered by | 30 Oct, 2017, 10:38: AM

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