Scientists stunned by ‘city-killer’ asteroid that just missed Earth

Asteroid 2019 OK gave a global fright on Thursday morning. At 71,880 km from the earth's surface, barely 1/5th the distance to the moon, the asteroid was dangerously close by space standards.

This rock is passed the earth with a speed of 24 km per second. The rock measured between 57 and 130 meters in diameter, and was big enough to wipe out an entire city, indicated the NASA Jet Propulsion Laboratory. Asteroid 2019 OK was the largest rock to get so close to the earth in years.

If it had pierced through the earth's atmosphere, the asteroid would have hit with over 30 times the energy generated by the Hiroshima atomic blast.

Thousands of near-earth asteroids are spotted by astronomers. But few come as close as Asteroid 2019 OK did. In 2017 alone, over 2,000 asteroids were seen passing at a safer distance from earth.

Does this give comfort to earthlings awaiting another massive asteroid heading this way on October 3, 2019, named 'Asteroid FT3', this is over three times the size of the rock that went past the planet on Thursday The rocky object measures about 340 meters in diameter.

Astronomers are certain that the chances of the asteroid striking the earth are remote. But Nasa has calculated that the rock will fly by the earth 165 times between 2019 and 2116. If it ever struck the earth, the impact force would be equal to 2,700 megatons of TNT.

On February 15, 2013, the Chelyabinsk asteroid measuring 20 meters in diameter had exploded over Russia. It had come barrelling into the atmosphere at speed of 69,000 kmph. The explosion triggered massive panic among local residents, injuring over 1,500 seriously enough to seek medical treatment.

To be prepared, astronomers attempt to pick up asteroids much before they pass by earth. But this is getting tougher as the late discovery of Asteroid 2019 OK proved.  The Chelyabinsk too could not be seen early as it was coming towards the earth from the sun's direction.