Asteroid '2019 OK' missed earth by a 'space' whisker

Narrow miss

Zooming past the earth at 24 km per second, 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.

The rock measured between 57 and 130 metres in diameter, and was big enough to wipe out an entire city, indicated the National Aeronautics and Space Administration (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. Nasa informed that the asteroid flew past the earth at 1.22 pm Singapore time. It was 10.52 am in India on Thursday. Academic research portal, The Conversation reported that the asteroid was discovered only days ago by the Brazilian SONEAR survey.

The rock’s presence was announced just hours before it zoomed past the planet. “The lack of warning shows how quickly potentially dangerous asteroids can sneak up on us,” analysed Michael J I Brown, an associate professor in astronomy, writing for The Conversation.

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 metres in diameter.

Astronomers are certain that the chances of this 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 earth, the impact force would be equal to 2,700 megatons of TNT.

On February 15, 2013, the Chelyabinsk asteroid measuring 20 metres in diameter had exploded over Russia. It had come barrelling into the atmosphere at speeds 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.