Sue ARVA has a moon rock and a mars rock. Both are the exact same size. Sue pours honey into a large glass. The moon rock barely floats on the surface but the mars rock sinks. Which rock has higher density?

In the same fluid, an object floats if its density is low enough, and it sinks if its density is high enough.

It doesn't matter which one is bigger, which one is smaller, how bitter or sweet the fluid is, what color the substances are, how much they cost, or what planet they came from.