The earth is constantly being hit by particles of dust, tiny rocks, and other space debris.
These small objects usually burn up high in the atmosphere, producing the shooting stars
you may have seen while looking up at the night sky.
But astronomers are always on the lookout for bigger asteroids, especially the ones
that may be on course to strike our planet.
While rare, these collisions with rocks from deep space do happen and the results can be
downright terrifying.
An asteroid just seven meters in diameter will explode with the power roughly equal
to the atomic bomb that was used on Hiroshima, leveling buildings up to a mile away.
A larger one hundred meter diameter asteroid has more power than the largest nuclear weapon
ever tested and could level and entire city!
But there are even bigger asteroids out in space.
And a run in with one of these would have a truly global impact.
An insanely giant asteroid, one around ten kilometers in diameter, would create an impact
crater one hundred and eighty kilometers wide and twenty kilometers deep.
Beyond just the impact it would cause worldwide earthquakes and mega tsunamis over one hundred
meters high.
Dust and ash thrown up into the atmosphere would cover the surface of the earth for years.
A massive die off of plants and animals would follow.
Basically the end of life as we know it.
And this has happened before.
An asteroid of roughly that size is what we think killed the dinosaurs.
And if an enormous asteroid the size of the earth were to hit, the planet would be completely
obliterated, leaving nothing but the earth’s core and creating a new asteroid belt between
Venus and Mars.
But don’t worry too much.
Giant asteroids the size of the one that wiped out the dinosaurs only hit the earth about
every fifty to one hundred million years.
Of course the last one was sixty-six million years ago so I guess you could say we are
due.