Glossary term: Escape Velocity
Description: Escape velocity is the minimum speed that an object must have to permanently escape from the gravitational field of a celestial body. The escape velocity at a distance r from the center of a massive body of mass m, is given by √(2Gm/r), where G is the gravitational constant. This means that the escape velocity depends on the radius of the celestial body and its mass. In the case of the Sun, it is 617.5 kilometers per second (km/s), and Earth is 11.2 km/s. It is 2.4 km/s for the Moon, which means that an object that wants to leave the Moon needs a lower speed than an object that wants to leave Earth, and therefore can enter lunar orbit at slower speeds.Related Terms:
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Term and definition status: This term and its definition is still awaiting approval
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