@GrayWolf2: However Krillin, Roshi and Yamcha were all fine yet they didn't come to help Goku because they knew they would be useless in the fight. Even if it lowers their power, by how much? If not moon level, they should atleast be able to blow up half or one fourth of the moon.
My argument is not only that Roshi can't moon bust, but rather the moon in DB is easier to blow up. Its because-
1. It appears to be much closer and smaller.
2. Roshi can blow up the moon, yet he can't beat the RRA weaklings or blow up their base.
3. Piccolo's beam reaches the moon in seconds yet Raditz dodges it, but the same Raditz fails to dodge gohan's headbutt....so this would make kid Gohan FTL, which is impossible.
4. King Piccolo is stated to be only a city buster. He even brags about city busting as if its a big thing.
(Keep in mind, the amount of energy required to blow up a city is only about 1 MT while it takes 30,000,000,000,000 MT to destroy the real moon.)
5. The moon in DB is different. It has oxygen and even gravity on it
This is why I don't consider anyone blowing up the moon before the late Saiyan Saga to be legit. The moon in DB must be smaller, closer and much easier to destroy.