World Asteroid Day 2021: How prepared are we for a dangerous collision?

June 30 is observed as the annual Asteroid Day, marking the anniversary of most dangerous asteroid-related event to happen on Earth in the planet’s known history - the Tunguska impact over Siberia.

Asteroid Day aims to spread awareness about the dangers posed by cosmic entities to Earth and ways to protect the planet, its inhabitants, as well as to mitigate potential disaster events in the future.

The history of Asteroid Day

Co-founded by late genius Stephen Hawking and a varied pool of personalities like filmmaker Grigorij Richets and Queen’s guitarist Brian May, the declaration was signed by 200 astronauts, scientists, and artists including engineer and part-time TV presenter Bill Nye and the evolutionary biologist Richard Dawkins.

Officially known as the “100X Declaration”, the instrument has received 22,000 signatures from private citizens, all of whom are not necessarily specialists. The declaration calls for improving the discovery rate of asteroids to 100,000 per year, hoping to achieve a 100-fold increase over the next decade.

What are asteroids?

Asteroids are minor planets situated in the inner solar system. Large asteroids are sometimes called “planetoids”. 

There are millions of asteroids in our solar system that hail from violent events in our solar system and bodies that never grew large enough to become planets. Most asteroids can be located between the orbits of Mars and Jupiter.

Composed mainly of minerals and rocks, asteroids are often confused with comets, which are made of dust and ice. Owing the proximity to our Sun, asteroids lack any comet-like characteristics. To be classified as an asteroid, objects need to have a diameter larger than one metre. 

The Tunguska event

On June 30, 1908 an explosion of celestial proportions took place near the Podkamennaya Tunguska River in Yeniseysk Governorate (now known as Krasnoyarsk Krai) in Russia. Due to its historical significance, June 30 is vastly known for the “Tunguska Event”.

In the aftermath of the explosion in the eastern Siberian Taiga, over 80 million trees spread across 2,150 square kilometres (830 square miles) of forest were flattened. According to archival eyewitness records, at least three people may have died in the event, although it's impossible to ascertain the real number.

Even though no impact crater was found, scientists remain confident that the disaster was caused by a stony object measuring upto 100 metres (330 feet), which is believed to have disintegrated at an altitude of 5-10 kilometres instead of directly hitting the Earth's surface.

Dangers posed by asteroids

According to B612 Foundation, which is a non-profit dedicated to planetary science especially on defence mechanisms against other objects in space, it’s certain that at some point in Earth’s life-cycle, it would be hit by an asteroid, but the foundation claims it’s still unsure when such a catastrophe would strike. 

In his final book, Stephen Hawking had also referred to an asteroid collision as the biggest threat to planet Earth. 

Major countries of the world are ill-prepared to tackle a potential collision. In a US Congress testimony in 2013, it was revealed that NASA would require almost five years of time to launch any mission requiring interception of an asteroid. 

(Images: Wikimedia Commons)