<Dd> P 2 = 3 π G V M ≈ 10.896 h r 2 g c m − 3 V M . (\ displaystyle P ^ (2) = (\ frac (3 \ pi) (G)) (\ frac (V) (M)) \ approx 10.896 \ (\ rm (hr ^ (2) \ g \ cm ^ (- 3))) (\ frac (V) (M)).) </Dd> <P> This way of expressing G shows the relationship between the average density of a planet and the period of a satellite orbiting just above its surface . </P> <P> For elliptical orbits, applying Kepler's 3rd law, expressed in units characteristic of Earth's orbit: </P> <Dl> <Dd> G = 4 π 2 A U 3 y r − 2 M − 1 ≈ 39.478 A U 3 y r − 2 M ⊙ − 1 (\ displaystyle G = 4 \ pi ^ (2) (\ rm (\ AU ^ (3))) (\ rm (\ yr ^ (- 2))) \ M ^ (- 1) \ approx 39.478 (\ rm (\ AU ^ (3))) (\ rm (\ yr ^ (- 2))) \ M_ (\ odot) ^ (- 1) \,), </Dd> </Dl>

Who found out the value of gravitational constant g