1. The problem statement, all variables and given/known data An astronaut standing on the Moon fires a gun so that the bullet leaves the barrel moving in a horizontal direction. What must be the muzzle speed of the bullet so that it travels completely around the Moon and return to its original location? How long does this trip take? Assume that the the free fall acceleration on the Moon is one-sixth that on Earth. 2. Relevant equations 3. The attempt at a solution Say the height of the guy is y. I got the circumference as 1092100m. So vt=1092100. t also satisfies y=(gt^2)/12. Then I get y=(9.74*10^11)/(v^2). I don't know where else to go with this.