the making of our solar system reaches
of violent climax 700 million years
after the pre-solar cloud first began to
collapse and earth is in the firing line
the gravitational chaos of Jupiter and
Saturn is battering the inner solar
systems planets and moons in an event
now known as the late heavy bombardment
a lot of the material in the outer solar
system these comets fell in towards the
inner solar system where they collided
with the inner planets and the moon
creating the craters that we see today
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some researchers believe collisions may
have repeatedly sterilized the earth and
that if life had formed it was wiped out
and had to start anew
but the impact of objects from space
along with their violets
may have also brought a benefit the
earth might not have all the water it
does today had it not been bombarded by
material from the outer solar system
some have speculated that much of the
water we have on earth is actually a
result of impacts from the late heavy
bombardment Korea
today 4.6 billion years after the solar
system's birth the ongoing if remote
danger of a massive asteroid strike
means the story is not over more
important though are the hundreds of
tiny asteroids hitting the planet as
meteorites studying them tells us that
the making of the solar system really
happened when and how we think it did
I'm holding a sample of the end a
meteorite the end a meteorite is a
fragment of rock that fell in Mexico
near the village of a yen Day in 1969
one of the components of the meteorite
are these calcium aluminum rich
inclusions these white objects that you
can see on the surface these are the
oldest known materials in the solar
system and we know this by age dating
with radiogenic isotopes in his
high-tech lab at UCLA Cosmo chemist Edie
Young in his colleagues carefully
examine tiny samples of ancient
meteorites there's a big white fragment
in the middle which we want to cut out
the labs precision lasers aim at the
fragments blasting out holes no wider
than a human hair
sophisticated analysis measures
radioactive elements which serve as
atomic clocks
in early 2011 Cosmo chemists in a
similar lab at Arizona State University
dated part of a North African meteorite
to an incredibly accurate 4.5 6 8 2
billion years old
the oldest material ever found on earth
older than the planet itself the most
important reason for understanding how
the solar system was made was to find
out whether or not we're normal when you
look out and look at other solar systems
being made with our telescopes today for
example in Orion and other places we
want to answer the question how normal
is the solar system
launched in 2009 the Kepler mission has
identified 1200 possible planets around
other stars
some systems have jupiter-sized planets
close to their Suns or in lopsided
orbits others have only small planets
crowded closely in the hot zone of their
stars our solar system however has its
planets in near circular orbits spread
out in a stable arrangement that seems
almost too perfect one of the great
surprises of the last decade as we
started to discover other planetary
systems was the fact that our solar
system seems to be one of the oddballs
most because our own solar system is so
regular is the solar system made by
processes that we can observe going on
today or are we somehow special
this goes to the point of whether or not
life is special
and that question is perhaps the most
important one of all as the life story
of the Sun and it's planets essentially
becomes the life story of life itself
humanity on earth and our ultimate place
alone or among many in the universe
you
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you