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  • 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.

Is It Possible to Stop an Asteroid?

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我們能阻止小行星撞擊地球嗎? (Could We Stop an Asteroid from Hitting Earth?)

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    林宜悉 發佈於 2021 年 01 月 14 日
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