March 23, Near Miss Day. Hurrah, we didn’t get wiped out by an asteroid

March 23 is Near Miss Day, an annual reminder of the day in 1989 when an asteroid nearly sideswiped Earth.

On this day in 1989, an asteroid that could have left a crater the size of Washington, D.C., harmlessly passed by the earth.

Don’t remember the mass panic, looting and media frenzy?  That because the 300-meter wide asteroid was only discovered nine days after our close encounter.

Designated 1989FC, it flew past the Earth at a distance of about 450,000 miles (684,000 km’s) traveling at 46,000 miles per hour and missed striking us by 6 hours.

About 450,000 miles is roughly twice the distance from the Earth to the moon.

“On the cosmic scale of things, that was a close call,” said Dr. Henry Holt.

Experts estimate that if the asteroid had hit the Earth, the resulting collision would have released energy equal to about 1000 atom bombs!

On land, the collision would have left a crater 5 to 10 miles wide and a mile deep; at sea, it would have caused devastating tidal waves.

 

Closest Calls

 

NEOs are comets or asteroids that orbit the sun and come close to – or even intersect with – the Earth’s orbit.

They can be just a few feet in size (whew!) or several miles in diameter (yikes!).

On average, Earth is hit once a year by elephant-sized asteroids, while bigger asteroids measuring 25ft across hit around every four years.

These are rarely witnessed as they either burn up in the atmosphere or land in the sea.

The asteroid suspected of killing the dinosaurs 65 million years ago is thought to have been about 6 miles wide.

Some astronomers think there may be at least a hundred objects that are half a mile or more across and that have orbits that send them skimming by Earth.

And there may be thousands that are a few dozen feet across.

 

Near Miss 2017

 

The closest NEO is expected to come between the Earth and the moon, and is an estimated 28 to 62 meters in diameter.

The good news?

These have already happened.

The bad news?  A near miss on St. Partick’s Day by asteroid 2017 EG3 — was only discovered 10 days after it zoomed by.

If an asteroid hits New York

Okay, on to what you really want to know.  What would really happen if an asteroid hit New York?

A recent study used a tool called Nukemap (yes, really!) to stimulate what a devastating impact would be like.

The first thing that happens would be the fireball from the initial strike, which would span nearly four kilometers in diameter for an asteroid only 100 meters in size.

(And that’s its size in space, not when it reaches the ground!)

Next is the catastrophic effects of radiation: thermal, not nuclear. This won’t poison you, but will simply cook you, albeit more slowly than the fireball does, covering nearly double the area of the fireball.

Buildings will be immediately leveled by the blast far beyond that, while extending more than twice as far out, structures will need to be demolished due to structural damage.

And finally, extending out for approximately 40 kilometers in diameter, every human being will experience burns on their skin simply due to the heat emitted.

All told, more than 2.5 million people would die if such an asteroid struck midtown Manhattan.

No immediate panic.   Experts predict we will be safe for the next 1.35 million years or so.

Sources: insurancequotes, nytimes

Siobhan O’Shea is a freelance writer. She writes about pretty much everything but especially likes to bring readers’ attention to new tech, marketing, human behavior, and other oddities.