Geoscience Reference
In-Depth Information
As we will see in
part 3
, nothing has happened to the Moon since its formation
except meteorite impact and the upwelling of basalt lava in the lunar seas, or
maria
. Our heavenly companion has no wind or water to erode and reshape its
rocks, no internal fires to reset its atomic clocks. Earth is a different story. So many
geologic events have beset our living planet that it would seem most unlikely that
we could ever find a rock or mineral whose atomic clocks retain their original age.
We even believe that the outer surface of the primordial Earth was molten. Before
theclocksofradioactivitycouldhaveretainedtheirtrueages,theEarthwouldhave
had to cool and solidify. Nevertheless, Australian scientists have found a number
of terrestrial zircons with ages of over four billion years and one that dates to 4.4
billion.
Few measurements in science escape revision for more than half a century.
Though scientists have made more precise measurements than Patterson was able
to do, his discovery stands unaltered. That the Earth, the Moon, and the meteorites
are 4.5 billion years old is one of the ground truths of science.
