In the last few days, we have read of a lot of asteroids passing by the earth, or making a close approach flyby. These space rocks often give rise to doomsday speculations from around the world. But what are asteroids? What is it made up of? Has any asteroid crashed on earth before? If you have any of these questions and so on, you have come to the right place. June 30 marks the celebration of Asteroid Day and so we answer some of the frequently asked questions about these space rocks. ‘Alien’ Asteroids Hiding in Plain Sight in Our Solar System For Billions of Years Found by Astronomers!

What Are Asteroids?

Asteroids are space rocks, minor planets inside the solar system. Large asteroids are referred to as planetoids. These rocky objects are bodies with Sun's solar nebula that never grew into large planets.

What Are Asteroids Made Of?

An asteroid is made up of rocks, metals and other elements. Some of them also contain water. Usually formed of loose rubble, they become rock-solid and also have iron. Some of the meteorites (part of an asteroid) which have been found on Earth have been detected with iron, nickel and cobalt.

Why is Asteroid Day Observed?

Asteroid Day marks the anniversary of the Siberian Tunguska event that took place on June 30, 1908. It is the most harmful asteroid-related event in the history of Earth in recent times. The UN proclaimed this day to raise awareness about asteroids. It also concerns how the Earth and the future generations on the planet can be protected from a catastrophic event.

Has An Asteroid Ever Hit Earth?

The Tunguska event after which the Asteroid Day is marked is a kind of asteroid collision. A large explosion occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate, Russia, on the morning of 30 June 1908. It is attributed to airburst of a meteoroid which was about 100 metres in size. This object disintegrated about 5 to 10 kilometres rather than colliding on the earth's surface. At least three people died with the impact. There was a limited scientific investigation on the event because of the lack of instruments and tech available at that time.

What Happens if Asteroid Hit Earth?

Hitting/collision of an asteroid or any other astronomical objects is considered as an impact event. The collision releases a lot of kinetic energy in the environment which causes damage on the ground. Effects could be shock waves, heat radiation, the formation of craters with associated earthquakes, and tsunamis if water bodies are hit. Human populations living in the impact area could be severely affected. The effect depends on the size, density and velocity of the object.

Which Are the Biggest Asteroids in Solar System?

There are three asteroids which are known to be the largest space rocks in the solar system. They are named 2 Pallas, 4 Vesta and 10 Hygiea and are about 400 and 525 km in diameter.

We hope we have cleared most of your doubts about these space rocks in the solar system. While there are very few chances of an asteroid crashing into the planet very soon, it is not impossible.

(The above story first appeared on LatestLY on Jun 29, 2020 01:50 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).