This
morning, while preparing for my round of sprints, I looked up at the dark early
morning sky. I do this each morning I do my sprints, because it is still
dark, and the stars in the firmament are quite visible. As I looked up, I
was fortunate enough to see a shooting star (meteor) streak across the
sky. Which got me thinking…
According
to geologists and cosmologists, the Earth has been in existence for
about 4.5 billion years. During that time the Earth and Moon have been
occasionally bombarded by meteorites of various sizes. It is believed that about
100 million years ago, Earth was struck by an object from space large enough
that the explosion and debris cast off, wiped out almost all life on Earth.
Fortunately for we humans, some population of then existent mammals survived,
ultimately thrived, and humans evolved from that humble new beginning.
Now we
have large telescopes, mathematics, and massive computational capabilities. We've
begun to realize how common it is for the Earth to be pummeled by these astral
objects – and how often we’ve missed being struck by other objects that
can cause similar damage and destruction.
Just
this year there was a large bus-sized object that passed the Earth inside the
orbit of the Moon. From a cosmological stand point, that’s liking having a
bullet miss your head by about a millimeter – a very close call.
It's enough to make you pause and wonder about how fortunate it is that after 100 million years, we're still here ...
Wednesday, November 23, 2011
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