The satellite revolves in a circular orbit and has a centripetal acceleration. This centripetal acceleration is caused by the gravitational attraction force of the planet.
m = mass of satellite M mass of planet R radius of the orbit
V linear velocity tangential to the orbit G = gravitational constant
Centripetal force = m V² / R
= gRGravitational Force = G Mm / R²
So, V² = G M/R
So, M = V² R / G = 500² * 8000 * 1000 / 6.67 * 10^-11
= 2.998 * 10^22 Kg
