Asteroids and their impact on Earth: All you need to know

On September 1, 2020, two large asteroids made a close approach to Earth. The Asteroids zoom past our planet about one-third the average distance to the moon. On September 6, 2020, another Asteroid 2010 FR passed by our planet and was twice as the size of the Pyramid of Giza. But the question arises that do these asteroids pose a threat to the Earth? 

Two large Asteroids made a close approach to Earth: All you need to know about Asteroids 2011 ES4 and 2020 QG5

As per NASA, space objects which pose a threat to Earth occurs once in a few million years. Also, all space objects are not dangerous. A car-size asteroid enters our planet's atmosphere and turns into a fireball which burns up before reaching the surface of the Earth. 

There are more than 1 billion asteroids with the diameter greater than 1 metre while those asteroids which may pose a serious threat to the Earth are larger than 30 metres. According to NASA, the asteroids which are of the size 140 metres pose a serious threat to our planet. However, it is worth noting that no asteroid greater than 140 metres has a chance of hitting the Earth for the next 100 years. 

Asteroids which are of the size 1 km or more in diameter have a chance of impacting our planet that too once in every 100,000 years. Also, comets are less dangerous and have a chance of hitting our planet once every 500,000 years. 

The space agency tweeted, 'Our #PlanetaryDefense experts are not worried about asteroid 2010 FR and you shouldn’t be either because it has zero chance of hitting Earth. It will safely pass by our planet on Sept. 6 more than 4.6 million miles away—that’s more than 19 times the distance of our Moon!'

Asteroid 2010 FR is classified as a Near-Earth Object (NEO) and is a Potentially Hazardous Asteroid (PHA). This Asteroid was discovered during the Catalina Sky Survey on March 18, 2010. 

What are Asteroids?

Asteroids are rocky objects orbiting around the Sun. They are also called minor planets. The count for the known asteroids is 994,383 as per NASA. 

Asteroids are classified into three categories. These are listed below: 

1- Asteroid Belt: Around 1.1-1.9 million asteroids are found between the orbits of Mars and Jupiter. 

2- Trojans: These share an orbit with the larger planets or moon but they do not collide with each other. They are found in the orbits of Venus, Earth, Mars, Uranus and Neptune.

3- Near-Earth Asteroids (NEA): These have orbits that pass close to that of Earth. The asteroids which cross the Earth's orbit are called Earth-crossers. As of June  2016, 14,464 NEA are known out of which 1,400 asteroids are classified as Potentially Hazardous Asteroids (PHAs). 

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