velocity of escape

: a velocity that if attained by a moving body (as a rocket) would enable it to escape from the gravitational field of the earth or a celestial body and move outward in space

the ability of a celestial body to retain an atmosphere around it depends on the velocity of escape at its surface

—R. H. Baker

this critical speed of seven miles a second is known as the earth's velocity of escape

—P. A. Moore

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