What happens when an asteroid actually hits Earth

What happens when an asteroid actually hits Earth
Trees felled by the Tunguska explosionPxhere
  • All it would take is an asteroid as big as a house travelling at 48,000 kilometers an hour colliding into Earth to have an impact equivalent to the Hiroshima nuclear bomb blast.
  • Any asteroid larger than one kilometer in diameter would push up so much dust and debris that it could block out the Sun and initiate another Ice Age.
  • Space agencies are keeping an eye on Near Earth Objects passing close to Earth but even their methods aren’t full proof.
Movies like Deep Impact, Armageddon, and even the animated The Good Dinosaur paint a vivid picture of what it would be like if an asteroid actually hit Earth. And, while the movies might be fictional — the reality of hundreds of asteroids whizzing past the planet is not.

The reports of asteroids bigger than the Pyramid of Giza and half the size of Everest passing by awfully close to Earth has gotten some scientists thinking that it’s only a matter of time before an asteroid will collide with the planet’s surface.

And it only seems more likely since, despite the Center of Near Earth Object Studies (CNEOS) and the Near Earth Object Coordination Center (NEOCC), recently illustrated how their methodology isn’t full proof.

An undetected asteroid dubbed 2019 OK missed crashing into Earth by a mere 73,000 kilometers on July 26 and space agencies didn’t know of it until the asteroid had already come and gone.

Size does matter

All it would take is an asteroid that’s as big as a house travelling at 48,000 kilometers per hour to release the amount of energy equivalent to the Hiroshima nuclear bomb blast.

That means concrete buildings for at least half a mile around the impact site would be flattened and any city would face a grim fate.

Increase the size of an asteroid to a 20 story building, the resulting impact would be anywhere from 25 megatons to 50 megatons — the same as the largest nuclear bombs that in existence today.

What happens when an asteroid actually hits Earth
The Chelyabinsk meteor that entered Earth's atmosphere over Russia on 15 February 2013 had the explosive energy of 200 kilotonnes of TNT Wikimedia

Any asteroid that spans more than a kilometer in diameter can’t be comparable to any weapon that humans have created. The one million megatons of energy that would strike Earth will result in 10 times the damage from Hiroshima.

And, like the asteroid that killed the dinosaurs, the dust and debris thrown back in the atmosphere would block out the sun. In case the asteroid lands in water instead of on land, the result wouldn’t be every different with tidal waves hundreds of feet high submerging whole coastlines.

‘The city killer’ asteroids

The asteroid that snuck past Earth, 2019 OK, is between 57 to 130 meters in diameter making it as big as a second tallest statue in the world — the Spring Temple Buddha in China.

And, it was travelling at a speed of 86,905 kilometers per hour when it whizzed past Earth.

If the asteroid would have collided with Earth, it would have gone off like a nuclear weapon with the force of 10 megatons of TNT.

When an asteroid of about the same size fell to Earth in 1908 — known as the Tunguska Impact — it leveled 2,000 square kilometers of forest in Siberia.

What happens when an asteroid actually hits Earth
Trees felled by the Tunguska explosion

‘Planet killer’ asteroids

The biggest of asteroid to ever hit Earth 65 million years ago was so devastating that it wiped out all the dinosaurs.

Not because the asteroid literally landed on them but because it threw up so much moisture and dust into the atmosphere that sunlight was nowhere to be found.

No sunlight meant no heat. The resulting drop in temperatures brought on the ice age and the dinosaurs were driven to extinction.

As of now, the CNEOS and the NEOCC, don’t have any asteroid that’s quite as big on their radars on a collision course for Earth — but they do know that they’re out there, like the 1998 OR2 that’s meant to pass by Earth in less than a year.

See also:

The 10 biggest asteroids that could crash into Earth in 2019

An asteroid only turns into a meteor if it falls to Earth

An asteroid nearly half the size of Mount Everest might be on a collision course for Earth in less than a year