1. The problem statement, all variables and given/known data One of Jupiters Moons runs on a circle with the radius r1= 420000km in T1=1,77d. How big is Jupiters Mass? Can you calculate the Mass of the Moon with this as well? γ = 6,672*10-11m3*kg-1*s-2 (gravitational constant) 2. Relevant equations I used following equation: T2=4*Π2*r3/γ*M 3. The attempt at a solution I solved the equation above to M = 4*Π2*r3/T2*γ Inserted the data and I get 1,399281324x1028 as a Result, which is wrong. What have I done wrong? I needed to translate the question to english, so if anything is bad explained I will try to explain it so good as I can.