2007-01-14 09:31:22 · 6 answers · asked by SusieeQ 3 in Science & Mathematics ➔ Biology
Unfortunately, the age cannot be computed directly from material that is solely from the Earth. There is evidence that energy from the Earth's accumulation caused the surface to be molten. Further, the processes of erosion and crustal recycling have apparently destroyed all of the earliest surface.
The oldest rocks which have been found so far (on the Earth) date to about 3.8 to 3.9 billion years ago (by several radiometric dating methods). Some of these rocks are sedimentary, and include minerals which are themselves as old as 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on North America, Greenland, Australia, Africa, and Asia.
While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it). This lower limit is at least concordant with the independently derived figure of 4.55 billion years for the Earth's actual age.
The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites. This involves measurement of three isotopes of lead (Pb-206, Pb-207, and either Pb-208 or Pb-204). A plot is constructed of Pb-206/Pb-204 versus Pb-207/Pb-204.
2007-01-14 10:11:30 · answer #1 · answered by gebobs 6 · 1⤊ 0⤋
About 4.6 billion years old.
This is based on many things, including the radiometrically dated age of the oldest terrestrial rock we've found. It is possible that the earth is slightly older, but there is additional evidence that puts the age of the sun at no more than 5 billion years old, which places an upper limit on the age of the earth.
2007-01-14 17:43:45 · answer #2 · answered by secretsauce 7 · 0⤊ 0⤋
I am uncertain as to its age. I would guess it is rather old in doggy years. But I do not think that any living human can give that an answer with certainty and knowledge that it is truth. If one believe in the science of Radio Carbon Dating it is around 4 billion people years old. But as it is moveing faster every year in its orbit that calculation could be way off.
2007-01-14 17:43:47 · answer #3 · answered by Yawn Gnome 7 · 0⤊ 0⤋
I'm not a scientist but I believe it's considered to be around 4 billion
2007-01-14 17:38:30 · answer #4 · answered by Anonymous · 0⤊ 0⤋
4.65 Billion years old.
2007-01-14 17:35:28 · answer #5 · answered by Shifter 3 · 0⤊ 0⤋
4.6bn old
2007-01-14 17:35:30 · answer #6 · answered by Anonymous · 0⤊ 0⤋