Space is vast and endless and even though we have been here on earth for 200,000 years, it’s only recently that we started exploring space. There are several mysteries in space we still don’t have any answers to, but we are making progress at a pace that was never possible before!
However, asteroids and meteors are the two entities that have often confused many. They became even more important when we found that the dinosaurs that lived on this planet were wiped out because of an asteroid hitting the earth.
Ever since this discovery, asteroids and meteors became the inspiration of many fictional creations, primarily movies that revolve around the topic of saving earth from an asteroid.
Space agencies like NASA and ESA have set up space monitoring systems that scan the space for a foreign entity that can enter our atmosphere. NASA calls its space monitoring system Sentry and uses advanced monitoring systems and computers to find the course of asteroids for the next 100 years.
Asteroid and meteors: the remnants
The confusion between the two terms became prevalent as we started using the terms carelessly. The entities in spaces are given certain names because they have distinguishing factors.
Let’s settle some of the misconceptions that surround asteroids and meteors.
Asteroids and meteoroids were once parts of planets. They are now the remnants of those planets which may have undergone some collision or other interspace destruction.
The asteroids and meteoroids are parts of them that are floating around in space, sometimes getting pulled by a gravitational field and hitting other objects.
What is an Asteroid?
Asteroids are large pieces of rocks that orbit the earth. Their composition is mostly rock and metal. They are categorized as rocks that are more than 10 meters in diameter.
An example of a large collection of asteroids is the asteroid belt that surrounds Mars and Jupiter. In the asteroid belt, it is estimated that there are more than 750,000 asteroids.
It was an asteroid that was responsible for the extinction of the dinosaurs. As their size gets bigger, the more impact power they pack.
There are also other asteroids impacts on earth, and they have left craters for us to see their devastation.
The Vredefort crater in South Africa is a prime example of the craters formed by asteroid impacts. It stretches more than 300 kilometers in width.
Even today, there are speculations of asteroids hitting the earth. There have been many reports written on an asteroid that had a very minor chance (1 in 70,000) of hitting the earth.
The researches tracked the asteroid again recently only to find that it is not on course.
Like we discussed before, scientists have already mapped out most asteroids that pose a threat to the world. However, uncertainties do happen like the Asteroid 2019 OK that went past earth on July 25th, 2019 with less than one fifth the distance to the moon, blindsiding the researchers who only got wind of the asteroid only hours before it was revealed.
The Asteroid 2019 OK was the size of a boulder, traveling at the speeds of 54,000 miles per hour. If it were to hit the earth, there would have been devastating local destruction.
Meteoroids or meteors: Less violent asteroids
Meteors are rocks that are smaller in size when compared to asteroids. They are broken pieces of asteroids hence their composition is also made mostly of metals and rock.
If any celestial body wants to reach the earth’s surface, it needs to go first through the earth’s atmosphere. Our atmosphere acts as a barrier against such enemies as they travel through it.
The friction between air and the meteor creates tremendous amounts of heat, vaporizing the foreign entity. These vaporizations are often called ‘shooting stars’ or ‘falling stars’.
However, when meteors are sizeable, they may not get fully vaporized. Such meteors have high chances of reaching the earth.
It is estimated that around 17 meteors reach the earth’s surface every single day. We hardly notice any of them because humans occupy only a tiny fraction of the earth’s surface.
Most of these meteors hence go unnoticed. The meteors that hit the earth surface are called meteorites.
They are comprised mostly of metal because most of the rock content gets vaporized early on. However, some do fall at places where there is a human population, and they have been recorded over time.
Some meteors explode once they are in our atmosphere due to the forces acting on them. One such example is the Chelyabinsk meteor that exploded in our atmosphere on 15 February 2013 over Russia, raining rocks as a result of the explosion.
This explosion also left notable damage to the man-made properties in the form of broken glasses and damaged buildings (estimates suggest that Chelyabinsk explosion damaged over 7000 buildings). More than 1,000 people were believed to be injured.
A much recent event of meteor explosion happened last year over the Bering Sea on December 18th. The explosion had a force 10 times that of the bomb that fell on Hiroshima.
We didn’t get to see any real-time images or videos of the same because it happened over the Bering Sea.
Meteors and asteroids are celestial bodies that do not differ much from each other except their relative sizes. The information that we have on them makes it clear why we should track them.
Incidents like 2019 OK shows us why there’s a need to have more tracking power to avoid such surprises. New initiatives like those recently seen from NASA in supporting space research are required for us to see far into space.