How much does planet Earth weigh?

It would be more proper to ask, "What is the mass of planet Earth?"1 The quick answer to that is: approximately 6,000,000,000,000 ,000,000,000,000 (6E+24) kilograms.The interesting sub-question is, "How did anyone figure that out?" It's not like the planet steps onto the scale each morning before it takes a shower. The measurement of the planet's weight is derived from the gravitational