Is It Possible to Stop an Asteroid?
Space has always been a source of fear and fascination for humankind. The secrets it
hides and its celestial objects that look like shooting stars mesmerize and intrigue
people. However, even modern technology can't save us from occasional confusion. Asteroids,
meteoroids, comets... What's the difference between these space phenomena? And which of
them can be the most threatening to our planet?
We'll tell you a bit later about the methods scientists invented to protect Earth if a
massive celestial object decides to pay us a visit. But first of all, let's figure out
the differences between the main space travelers: asteroids, meteoroids, and comets.
Comets are solar system bodies that consist mostly of ice. When they approach the sun,
comets leave a trail of ice, rock particles, and dust. They typically appear in the outer
solar system.
Asteroids are sometimes classified as minor planets. This means that their size is pretty
impressive, and they orbit the sun. What is more, some of them even have moons of their
own.
As for meteoroids, they are much smaller than asteroids and can be as tiny as sand particles.
They are, in fact, debris drifting in space in orbit around different celestial bodies.
Their speed is higher than that of asteroids, and they can consist of various materials,
from ice to iron.
To avoid further confusion, we should also distinguish between meteoroids, meteors, and
meteorites. Once again, meteoroids orbit the sun. However, if they break through the atmosphere
of our planet, they begin to burn (that's when they start to look like shooting stars).
At this moment, they change their name to meteors. Only after they survive this plummeting
descent and hit the surface of the planet are they called meteorites. A study in 1985
suggested that a human being would be hit by a meteorite every 180 years.
Another interesting thing connected to meteors is meteor showers, during which a lot of meteors
can be seen in the sky in a short period of time. The most famous meteor shower happened
in 1833 when more than 10,000 meteors were seen every hour. This means that about 15
meteors were noticed every second! This meteor shower was named the Leonid meteor shower.
Meteorites make the planet 110,000 tons heavier every year, according to the estimations of
scientists. The Planetary Science Institute states that more than 500 meteorites reach
the surface of the planet yearly, but only 10 or fewer are ever recovered. The main reason
is that these space objects mostly fall into the oceans and seas.
The largest meteorite known to people is the Hoba meteor, situated in Namibia, Africa.
It was first spotted by a local farmer in 1920. This huge object most likely survived
thanks to its content: mostly iron and 16% nickel. It measures 9 ft by 9 ft by 3 ft.
As for its weight, it's a whopping 66 tons.
In any case, however big and fast meteorites are, they can't cause the same damage that
Earth can experience if an asteroid were to hit. And there is evidence of what happens
when a stray asteroid crashes into the planet.
The asteroid belt between Jupiter and Mars is home to many asteroids. However, from time
to time, they leave their orbit and move closer to Earth. Luckily, we haven't had any huge
asteroids hit Earth in the past several thousand years, but it has happened.
The most famous crater left after the impact of an asteroid is probably the Arizona Meteor
Crater, which appeared more than 50,000 years ago. This impact crater is about 1 mile in
diameter and has a depth of 560 ft.
That's not the only impact crater we know about. There are approximately 180 documented
sites. Some of them are enormous! For example, Vredefort Crater in South Africa has a radius
of 118 miles. It's the largest known impact site on our planet.
Most people believe that the asteroid that fell near the coast of the Yucatan Peninsula
in Mexico caused the most disastrous impact in the history of Earth. The asteroid raised
such a huge cloud of dust that it completely changed the climate of the planet. According
to scientists, this celestial object was to blame for the extinction of dinosaurs about
65 million years ago.
However, our planet had a much more serious encounter 3 billion years ago. An asteroid
that fell to Earth was even bigger than the one that killed the dinosaurs. In addition,
its speed was extraordinarily fast: more than 12 miles per second! Scientists think that
this asteroid fell somewhere in South Africa, and this led to the changes in the tectonic
structure of the planet.
Nowadays, with the development of modern technologies, asteroids don't present such a terrible threat.
Every year, according to NASA specialists, an asteroid as big as a car enters Earth’s
atmosphere, turns into a spectacular fireball, and disintegrates before it has a chance to
reach the surface of the planet. On the other hand, a celestial object as large as a football
field hits Earth every 5,000 years, causing serious damage. Once every several million
years, our planet collides with a space body so large that it causes a global planetary
catastrophe.
As you can see, such an encounter can turn our peaceful life into a disaster movie. Therefore,
a question arises: is it possible to stop an asteroid that threatens life on Earth?
The answer is yes. In fact, there are 3 solutions.
1. ARM (Asteroid Redirect Mission)
NASA is currently working on creating the first robotic mission. This mission will be
connected with the potential threat that asteroids present to our planet.
The first task of the robotic mission will be to approach a large asteroid located close
to Earth, collect a multi-ton rock from its surface, and redirect the asteroid to a stable
orbit around the moon.
This will serve a double purpose. First of all, specialists will gain experience in removing
a potential threat to our planet. Secondly, astronauts will return with a sample of an
asteroid in the 2020s.
2. DART (Double Asteroid Redirection Test)
The DART mission will be the first demonstration to see if people can use the kinetic impact
technique to make an asteroid change its course in space.
Scientists have already chosen the target: it will be the binary asteroid 65803 Didymos.
This space body will be spotted close to Earth in October 2022, passing just 620,000 miles
away. The DART mission will impact the asteroid's secondary body, crashing into it at a speed
of 4 miles per second. If everything goes as planned, this collision will change the
course of the moonlet around the primary body by a fraction of 1%.
Such a small number may seem like nothing, but it can make a huge difference when moving
the course of an asteroid hundreds of miles away from our planet.
3. DE-STAR mission
DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) sounds like
something from science fiction!
Such a system could potentially destroy asteroids, comets, and other dangerous near-Earth space
bodies that pose a high risk of impact. If DE-STAR were created, it would consist of
satellites that would gather solar energy and convert it into an array of such powerful
lasers that they would be able to disintegrate an asteroid.
At the moment, this system is still theoretical. However, some scientists state that the technology
to make the idea of the super-laser come true already exists. People just need to construct
a DE-STAR model big enough (perhaps as big as 6 miles across).
Oh, have you already pictured a laser blast scattering asteroids? Sorry to disappoint
you, but DE-STAR (with a diameter of 328 ft) would just slowly push asteroids and comets
out of their orbits and away from Earth. As for a large-scale DE-STAR system (say, 6 miles
in diameter), it could potentially destroy an asteroid with a diameter of 1,700 ft, but
this process would take approximately one year.
In any case, whatever solution scientists choose, Earth won't helplessly wait for a
huge asteroid to crash into its surface.
Do you believe in the possibility of a celestial body coming into contact with our planet and
causing a natural disaster? Tell us in the comments below!
Remember to like the video, and don't forget to subscribe to our channel! This way, you'll
always stay on the Bright Side of life.