Run away speed (Velocity of Escape) : If the initial speed of an object is less than a certain value, the object will rise only a certain distance, and then the acceleration caused by the star's gravity will finally cause it to fall. If the initial speed reaches a certain value, the object will completely escape the gravity of the star and fly away from the planet. The speed at which an object needs to escape the gravitational pull of a star is called Run away speed. The minimum speed required for an object on the surface of a celestial body to escape the gravitational bonds of that celestial body and fly into space. For Example, the Earth runs away at a speed of 11.2 km/s (the second cosmic speed).

Run away speed

Run away speed ：V_e²=2GM / R

here:

G =Gravity is constant number = 6.6726 x 10^-11N-m²/kg²

M =planet Quality

R = planet radius