Calculates how strongly stars, planets and moons attract each other at what distance. The force of attraction or gravity increases with the two masses involved and decreases with the distance between the two objects. The gravitational force is calculated as the gravitational constant times the mass of the first body times the mass of the second body divided by the square of the distance between the two. Mathematically expressed, the formula for the calculation is F = G * m_{1} * m_{2} / r² . The masses and the distance can be entered directly, or the predefined values for the sun, earth, moon, Jupiter and their distances can be selected. These can also be multiplied, for example as 2.5 * Earth, in order to calculate with an exoplanet with two and a half times the mass of our home planet. The force is output in Newtons (N), a corresponding prefix such as mega- (M, 10 to the power of 6) or giga- (G, 10 to the power of 9) can be selected, but the results are generally found above exanewtons, i.e. 10 to the power of 18.