Scientists know the Universe is governed by 13 fundamental constants of physics, and the relationship between the volume of the Earth and the Sun is 1310.
About 100 million years ago, sea levels were about 300 metres higher than at present because of changes in the volume of ocean basins due to movement by the Earth's techtonic plates.
Because there are more DA14s filling interplanetary space than YU55s, a 50-foot asteroid can be found in a smaller volume of space, on average, and thus closer to Earth, than a 150-foot one.