The Threat of Asteroids to the Human Race

With an asteroid set to pass close to the Earth, it’s time I explain why near-misses with space rock send chills down the spine of everyone who’s concerned with astronomy and explosives. Asteroids may be small, but it is no doubt that they are tremendously dangerous. If you don’t think so, well, with some luck, I suggest you contact the Dinosaurs and ask them what knocked off their civilisation from the top of the Biosphere. I’ll give you a hint. An asteroid hit the Gulf of Mexico about 65 million years ago. It was a 6-mile wide asteroid that carved out a crater that is about 300 miles in radius. Its called the Chixculub crater. When it hit, it is predicted to have created earthquakes much more powerful than the one that struck Valdivia, Chile all those years ago in 1960.. 

An Artist’s rendering of the Asteroid impact which wiped out the Dinosaurs

An asteroid collision of such scales is rare; there is about one such collision in a hundred million years or more. But, it doesn’t take such a big rock to do alot of damage. In 1908, an asteroid or a comet exploded above the Tunguska region in Russia. The explosion occured at an altitude of 5-10 km, and it shattered glass panes in houses considerable distances away. It had the same energy release as a magnitude 5 earthquake on the Richter scale and flattened trees over an area of 2150 square kilometers! Estimates in the size range wildly from 60 m to 190 m. Its predicted energy release was a 1000 times more than the infamous Atom Bomb dropped onto the town of Hiroshima in the year 1945. 

The Tunguska region after the blast

The reasons why Asteroids release such vast quantities of energy is clear: They maybe small in size, but they are massive! With masses of less than 0.0000000001% (well most of them) of the Earth, you may quickly dismiss their mass. But, never forget to keep this in mind. The Earth is 6*10^24 kgs of rock! If you are familiar with the concept of momentum, you will know that the higher the mass of the object, the greater the momentum it hits the Earth with. 

Now, masses are not the end of the story. Its common knowledge to everyone, even the layman, that gravity is the reason why we stick to the surface and do not go flying off into space (along with everything else!). The same holds true for asteroids. The gravity of the Earth accelerates these already fast-moving objects, which increases the momentum it contains. When they hit the Earth, the change in momentum (i.e the Force) released is tremendous. Like I said, it is like an Earthquake of epic proportions!

 Bare in mind even asteroids such as the Tunguska event happen about roughly every few millenia. The smaller the asteroids, the greater the chances of them hitting the Earth. In fact, those brilliant streaks of light in the night sky that we see, which we call Shooting Stars, are in fact tiny asteroids or parts of them (meteors, or meteorites, depending on whether or not they hit the surface)! 

Now that I have talked about asteroid strikes with considerable detail, I will now enlighten you with ways with how such threats might be combated. First of all, these things need to be detected. Since they are tiny, detecting them amongst the vast number of celestial objects in the Cosmos is hard. But, it is not that we haven’t tried. NASA has dedicated large amounts of money for detecting such threats posed by asteroids. It is NASA’s aim to locate and map each and every asteroid in our near vicinity that might pose a threat to human life. 

After detecting the asteroids, something needs to be done about diverting them from the collision course. There are multiple ideas of how to do this, of which two strike me as interesting and feasible. The first one involves detonating a nuclear bomb on the asteroids surface and blasting it to smithereens. Now this is tougher than it sounds. An asteroid moves through space at many kilometers per second! Bombs take a while to be detonated after they are launched; they need to be perfectly timed. And there is the added threat that by fragmenting the asteroid, you make it even more deadly!

The second way involves launching a spaceprobe and getting it to pass nearby the asteroid, and maintaining its nearness with the asteroid in question. Asteroids have a smaller mass compared to other objects and thus have smaller gravity. If a spacecraft gets sufficiently close to an asteroid, it can “change” the course of the asteroid by virtue of its mass. It can be used to carry the asteroid into a safer orbit. 

Asteroid strikes do happen, and its inevitable in the future.Jupiter plays a big hand in reducing the amount of asteroid strikes and comet strikes in the inner solar system. By virtue of its immense mass, Jupiter frequently attracts vast swathes of rocks in the form of Asteroids and comets and ejects them out of the Solar System, prematurely ending their seemingly bloodthirsty quest to destroy life on Earth. So, the next time you see Jupiter in a picture, or in the sky, feel a deep sense of awe and wonder at our planetary bodyguard. 

Humankind shall always have threats to its survival. There shall both be internal as well as external matters which shall always look to hinder our development and remove the mark of the Human race from the Universe altogether. It is therefore our duty as a civilisation to monitor and contain these threats. Asteroids are known to have ended prospering civilisations in the past, and if we don’t do something in the future, such as migrating to a another planet, we might just as well be an asteroid’s next victim.