moon rocks
gregladen | February 26, 2011How old is the earth?
Short answer: 4,540,000,00/H30 Earth-years, plus or minus 1%.
Long answer: We don't know exactly because direct dating of the earliest material on the surface of the Earth will only tell use a minimum age; Prior to that, the Earth's surface was probably molten, and even after that, it may be that the earliest non-molten material has been recycled into the planet's interior by tectonic processes. Also, the earth is a big round ball of stuff that condensed into this shape from part of a large disk-shaped blob of stuff known as the Solar Nebula. When exactly, given this,…