Basic HTML Version
by Julian Nott
renderings by Don Davis
SAVING THE PLANET
FROM ASTEROIDS
Cause For Reflection
W
hile we all enjoy the beauty surrounding us in Mon-
tecito, we are often reminded by tremors that this is
“Earthquake Central.” We hear and read continually
that the question is not if “The Big One” is coming, but
when. Just imagine if you could predict the exact time and place of every
major earthquake, most midsized ones and many small quakes for the
next 100 years. And suppose you could also stop those earthquakes
from happening?
That is what former NASA astronaut Ed Lu is preparing to do, to pro-
tect us from a rather similar kind of natural disaster, asteroids striking
the Earth. He is leading a unique project to launch a telescope into
space that will map all the asteroids that orbit close to Earth. While
earthquakes are unpredictable, orbits in space can be calculated very
precisely. Once asteroids are found, it is possible to discover exactly
if, when and where they will strike the Earth.
And better still, if a dangerous asteroid is discovered well in advance,
it will be fairly easy to prevent it from ever hitting Earth. No need to send
Bruce Willis into space with a nuclear warhead, as he did in the film
Armageddon; all that is needed is a firm push to alter the asteroid’s orbit
by a very small amount.
Why Do Asteroids Matter?
Probably the most famous asteroid is the one that wiped out the dinosaurs.
But asteroids, large rocks from space, have hit the Earth throughout its his-
tory. And they keep coming: as recently as March 15 a large asteroid came
right through our neighborhood, closer to Earth than many communications
satellites. It had the prosaic name 2012 DA14, but crucially 2012 signifies it
was only discovered last year. It might have had a slightly different path and
slammed into Earth almost unannounced and with the destructive energy of
500 Hiroshima bombs. It might have landed in a remote region or it could
have obliterated an area the size of metropolitan Washington, D.C. or the
entire San Francisco Bay Area.
And to make sure earthlings did not miss the message, the same day and
completely unannounced a small asteroid streaked across the sky, crashing
down in Chelyabinsk, Russia, doing damage across a distance of 300 miles
and injuring 1,400 people.
It has now been established that there are literally a million asteroids 150
feet across or larger orbiting the sun in the vicinity of Earth. But so far only
about one percent have been discovered. Many of them pass between the
Earth and the sun and cannot be seen against the sun’s glare. Only aster-
oids that pass on the night side can be found. As astronaut Ed Lu puts it, we
know more about the nearest one million stars because we can see them all
in the night sky, than we do about the nearest one million asteroids.
120
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