According to
NASA a massive meteor crashed into the Atlantic ocean with the force equivalent
to an atomic bomb. However nobody had a clue that it had happened. Despite
having the destructive power of the Hiroshima bomb (around 13,000 tons of TNT),
this particular fireball was actually pretty small, exploding over the South
Atlantic ocean on Feb 6th, 2016.
In
comparison, the Chelyabinsk which struck in 2013 reportedly weighed around 10
tonnes and released roughly the energy equivalent to 500,000 tonnes of TNT.
Contrary to Hollywood's depiction of meteors it is rarely the impact that
causes the most amount of collateral damage. Instead it's the energy that's
released when the meteor breaks up in the atmosphere.
The event was
reported on the NASA/JPL Near-Earth Object Fireball page, which lists some of
the brightest such things.
The
Chelyabinsk meteor caused over 1,000 injuries when it exploded above the city.
Travelling at anywhere over 33,000mph these objects will superheat, compress
and then 'vaporise' many kilometres above the Earth's surface.
It's this
process which causes the huge release of energy and in the case of Chelyabinsk,
caused almost a city's worth of windows to shatter, injuring thousands in the
process. As astronomy blogger Phil Plait points out this occurrence, while
dramatic, is actually not that uncommon.
"Impacts like this happen several times per year on average, with most going unseen."
So why
hasn't a city or populated area been hit by a meteor yet? Well Plait has a
beautifully simple answer:
"The Earth is mostly water, and even where there’s land, it’s sparsely populated overall."
Despite
worries of population overcrowding, the human race is not as big a target for
potentially devastating meteors as we'd like to think. That said, NASA still
runs the Near Earth Object Program, an initiative which tracks thousands of
objects which could potentially collide with Earth over the next 100 years.
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