Asteroids coming near earth in the next hundred years
Rest assured, major asteroids will not be coming near Earth in the next hundred years. Nevertheless, the science behind the prediction and prevention is interesting.
Will asteroids hit the earth within our lifetime? Probably not. The National Air and Space Administration (NASA) monitors the orbital paths around Earth for asteroids that might come into contact with Earth’s atmosphere, and it knows of no such possibility. A meteor (the name for an asteroid when it enters the Earth’s atmosphere) will most likely not be the cause of an Armageddon in the next eras. This likelihood is reassuring, but enough uncertainty exists in the field to give scientists room to speculate. About 3.9 billion years ago, meteors hit the Earth repeatedly, and a sizable impact is what is believed to have killed the dinosaurs. As a result, it would be foolhardy to believe that such an occurrence could never happen again. However, numerous telescopes monitor the atmosphere looking for near Earth objects (NEOs), and no major impacts are seen or predicted.
Even though Earth is safe from a major impact, smaller
meteors continually bombard it. The atmosphere protects us
from these meteors, breaking them into small pebbles. In fact,
the atmosphere can destroy a meteor up to 30 feet in diameter.
The fragments of broken meteors do reach the ground (which is
why museums have samples on display), but there is no record
of fatalities as a result. Of course, a car window may be
broken or a roof damaged, but, for the most part, a meteoric
impact happens over Siberia or other rural zones.
The most extreme example of a rural impact was in Tunguska,
where a meteor 30 to 60 meters in diameter exploded in the air
about three miles above the ground. Despite the meteor not
exploding on contact with the Earth, it still released an
amount of energy of nuclear proportions. The area around the
explosion was scorched, and people over 120 miles away felt a
strong shockwave.
Although the chances that a larger meteor would hit the
Earth are slim, scientists can still predict the effects of
such an event. Clearly, life around the impact site would be
wiped out. More significant, though, is the cloud of dust and
vapor that would put the Earth into a nuclear winter, harming
people and basic life sources like crops, animals, and water.
With this alarming evidence in mind, scientists have created
two methods of preventing this type of disaster. Broadly, they
can be categorized by means of destruction and deflection.
Destroying a meteor is similar in theory to President
Reagan’s early plan for protecting American against Soviet
attack in the 1980s: destroy the object before it enters the
Earth’s atmosphere. An asteroid could be broken into smaller
pieces while still in space by nuclear detonation. Although
this idea sounds ideal, it would be very difficult to
implement. The correct aim, the correct force of the hit, and
the most effective explosion of the asteroid are all very
difficult to achieve at once. Another option for prevention is
termed as deflection. Although specific examples are not
available, the broad idea is that nudging or bumping the
asteroid would alter its trajectory path away from Earth,
essentially putting the Earth out of harm’s way. While it is
easy to become caught up in the frightening idea of a meteor
destroying the Earth, it is important to remember that objects
from space have brought materials to Earth that are essential
for humans and the atmosphere, namely carbon. The extinctions
of species caused by meteors also caused evolution to occur
more rapidly (think of humans trying to co-exist with
dinosaurs).
Author: Ursula Gross About Author:
Ursula Gross is a freelance writer.
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