Asteroid Hits Earth! How the Doomsday Scenario Would Play Out

We can't protect ourselves from incoming ordnance, but we have a pretty good idea of what a big hit would be like

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Space is an exceedingly random place. Everything in the known universe may be governed by some pretty hard laws of physics, but so are BBs in a jar when you shake them up and down. That doesn’t stop things from getting very chaotic inside. The same extreme arbitrariness is worth keeping in mind as we contemplate our planet’s close brush with an asteroid this week.

(FROM THE ARCHIVESAsteroids: Whew!)

As TIME reports in this week’s issue (available to subscribers here), astronomers have known for the better part of a year that asteroid 2012 DA14—a medium sized, 150 ft (50 m) rock weighing 143,000 tons—was closing in on us. They knew that it would miss us too, by 17,200 miles (27,700 km).  That seems like a big number, but in a solar system measured in billions of miles and a universe measured in billions of light years, it vanishes to inconsequence. The fact is, the odds of our getting clobbered by the rogue rock were in some ways the same as its missing us—at least when you fold into the equation how little it would have taken to change both its course and its impact. So what would those x-factors have been that would have turned a near miss into a true disaster, and what would the nastiness that resulted have looked like?

Let’s start by making 2012 DA14 bigger—though it hardly needs the extra bulk. At its current size, it would produce a blast equivalent to 2.4 megatons, or 180 Hiroshimas, after it entered our atmosphere.  A significantly bigger asteroid would produce a significantly bigger blast and there’s no shortage of those cosmic missiles out there. Astronomers estimate there are 2,400 objects in the vicinity of Earth that are at least 0.5 km (0.3 mi) across and 860 of those are a full 1 km (.62 mi.). A 0.5 km rock would produce a 5,000 megaton blast—not to mention a 7.1 Richter-scale shock. Let’s split the difference then, but err on the size of conservatism: Our death rock would be a comparatively modest 100 m, or 330 ft., across.

(MORE: The Committee to Save the Planet: Who Watches the Asteroids?)

The speed of the object would make a difference too. Over the course of the past several months, 2012 DA14 has been clipping along at a brisk 17,450 mph (28,000 k/h), and that’s what packs it so full of energy. Just like a baseball that’s tossed lightly at your chest doesn’t hurt you but a fastball thrown by a pro player would crack your sternum, so too does velocity turn a nuisance rock into a unguided missile. But the speed of 2012 DA14, not to mention its angle of flight, saved our hides too. A difference of a few centimeters per second—faster or slower, depending on when and where the force was applied—would have been enough to shift the asteroid’s trajectory and put us in its crosshairs. A random bump from a smaller bit of space rubble could have done that trick, as could a gravity tug from a larger object the asteroid passed. So could the light of the sun.

Solar energy becomes heat energy when it strikes an asteroid,  and that can exert a physical force all its own. A rock with a bright surface reflects more light away and feels less of an effect. A darker surface absorbs more and gets nudged more. And solar flares—which occur unpredictably—can mix things up further, exerting a sudden pressure that compounds the sun’s the slow, steady one.

“Heat can push these bodies around,” says Paul Chodas, a research scientist in the Near-Earth Object (NEO) Program Office at NASA‘s Jet Propulsion Laboratory in Pasadena. “We can determine future trajectories out to about 100 years, but there are uncertainties like this that make it difficult to forecast as reliably for the smaller objects.” Asteroids that have traces of water—and in a cosmos as heavily  hydrated as ours that’s not uncommon—can outgas tiny amounts of vapor, which act as small, natural thrusters that perturbs the flight path further. Given all of those x-factors, it’s hardly unreasonable to say that 2012 DA14 might have easily gotten nudged our way.

The first word of the incoming missile would likely come from one of three main observatories NASA has assigned to scan the sky for cosmic ordnance all day, every day. But amateurs and academic observatories around the world could spot it too (it was an amateur who discovered 2012 DA14, in fact). We also might not see it at all. Like fighter planes taking advantage of natural blind spots in the sky, asteroids can approach from the direction of the sun, making them impossible to see until it’s way too late. “The smaller ones aren’t even visible until they’re on the way back out,” says Don Yeomans, head of the NEO office.

(MORE: Duck! Close Shave With an Asteroid Coming)

But imagine we saw our 100-meter asteroid when it was, say, eight months away. NASA would first send out word to the rest of the world’s astronomers, who would begin training their telescopes on it too, something they do already even for benign rocks. They measure light output, rotation rate and trajectory, conducting their own plight-path calculations to help confirm what the NASA software is spitting out. Radio-telescopes at Goldstone Observatory in the Mojave Desert and the Aricebo Observatory in Puerto Rico would swing into position as well, bouncing signals off the rock to determine distance, velocity and doppler shift—or the stretching or compressing of the signals reflecting back to determine the degree to which the object is moving toward or away from the observer.

“There is a small army of worldwide professionals and amateurs doing this,” says Yeomans.

The good thing about so much crowd-sourcing is that when hundreds or thousands of astronomers reach a conclusion, you can be pretty sure it’s a solid one. The bad thing is that when that conclusion is one you don’t like, there’s no court of appeal. In this case, let’s imagine that the conclusion is a truly bad one—that our football-field sized rock would be targeting a populated area. And for the sake of doomsday pizzaz, let’s make that populated area New York City.

(MORE: Deep Space Industries: The Company That Wants to Mine Space)

The five boroughs that comprise the city have a total area of 469 sq. mi., including 164 sq. mi. of water, and are home to 8.3 million people. A rock barreling in from space would likely be made of some kind silicate—the overwhelming majority of asteroids are—which means it wouldn’t survive the blazing heat of entry intact and instead would explode in the sky. Trajectory analysts at NASA and elsewhere would be able to forecast the exact date, time, place and angle of entry, so imagine Central Park, at high noon, on a work day, at an angle of entry that maximizes the possible explosion.

As it happens, we have a very good idea of how things would unfold in a situation like that since an extremely similar scenario played out before, on June 30, 1908, near the Tunguska River in Central Russia. At 7:14 that morning, a massive blast from what is calculated to have been a 100-meter asteroid occurred somewhere from 3 to 6 mi. (5 to 10 km) above the surface. The region was heavily forested and lightly populated—which was a very good thing—but the devastation was nonetheless stunning. Roughly 80 million trees were leveled or incinerated in a footprint of destruction extending 830 sq. mi. (2,150 sq. km). The energy released by the blast is estimated to have been 30 megatons—or 1,000 Hiroshimas.

An 830 sq. mi blast ring has a radius of 14.4 mi. (23.2 km). Position that over New York City and you’d have destruction reaching deep into Queens in the east and Staten Island in the South; west to Paterson and Montclair, NJ; and north to Yonkers and New Rochelle, NY. Manhattan, the Bronx and Brooklyn would be swallowed whole. Evacuation in advance of the blast would be a massive challenge, since the array of bridges and tunnels that connect the boroughs are natural choke points. The many months of notice the residents would have before the big day arrived would make things a bit easier, but fleeing from an asteroid is very different from fleeing from other kinds of disasters. People evacuating in advance of, say, a hurricane can usually just load up their cars and go, since even after a superstorm like Katrina, most of them will simply be turning around and coming home. After a Tunguska-like blast, most people would not have any home left at all.

(VIDEO: How to Save Earth From Killer Asteroids By Using a Paintball Gun)

As with a nuclear blast, the devastation would be greatest at the epicenter of the event and fade the farther away you moved, and while there would be no radiation to contend with, the immediate destruction would be pretty much the same. In a 6.5 mi. radius, all that would be left of most buildings would be the foundations, though some sturdier, reinforced structures like stocky old banks might survive. Out to 11 or so miles, multi-story buildings would be skeletonized—their curtain walls stripped away and only their frameworks left standing. Small, individual family homes would be destroyed completely. It would not be until about 20 miles away that most tall buildings would survive—windowless, to be sure—and some single-family dwellings would too. The economic damage—nationally and globally—would be incalculable.

Tunguska-type hits are rare—even smaller asteroids like 2012 DA14 strike the planet only once every 1,200 years or so. Bigger objects—on the order of 2 km (1.25 mi.)—hit only every 100,000 years or so. The stakes being what they are, though, that’s little comfort. When you’re dealing with something like asteroids, all it takes is one. That’s something the dinosaurs of 65 million years ago could tell you—if an asteroid hadn’t killed them all, of course.

TIME MAGAZINE: (Very) Close Encounter

123 comments
Jones71544621
Jones71544621

I remember how anxious I was as we heard rumors of an asteroid hitting earth. But I believe it will happen in the future. The Bible clearly states that and many will die as a result. Too annoying if we think it seriously. We watched some Hollywood movies but the real one will be more shoking I guess. 

allenwang@google75.com
allenwang@google75.com

I Always Believe That An Asteroid Would Hit Earth Someday Because We Are Living In The Last Days

On Earth As Predicted And Prophesied By People Who Know John's Revelation Of The End Times!

CharlesEdwardWeber
CharlesEdwardWeber


I suspect that you will find interesting a hypothesis that most of the large lava flows on Earth and Mars result from disruption of the crust at the antipode (opposite side of a sphere) from a huge meteorite impact. You may see it discussed in http://charles_w.tripod.com/antipode.htmlfor Earth andhttp://charles_w.tripod.com/dweber/mars_volcanos/mars_volcanos2.html for Mars.

The chance that there would be a lava flow at the antipode of each of the large known meteorite impact sites of the same age by sheer coincidence is extremely small.

.

Sincerely,Charles Weber

JMLBosmansMDPhD
JMLBosmansMDPhD

The spot that is exactly under the centerpoint of an explosion (either an asteroid or a nuclear bomb) is not called the 'epicenter' but the 'hypocenter'! Epi = upon, so epicenter only pertains to something that is happening in the earth under the spot (the center of an earthquake). Hypo = under, which is the case when something explodes above you: you will be 'under' (hypo) the center of the explosion. This error is nearly universal. For many people, the 'epi'center is the very center of something. It is quite pitiful that even a science journalist commits the error.

ChristopherDack
ChristopherDack

God ?! . Sigh .. You claim to know what "your " god loves and does Lynnhooker ? . Science is about finding out no matter how we dont like the results sometimes. God is about sticking your head in sand and saying " no matter what im right your wrong "

ekantarovich
ekantarovich

If we added planets to Earth, then we'd be bigger than any asteroid.

LynnHooker
LynnHooker

Frankhy you really do not have a clue. This "god" you keep dissing is not who your little brain thinks he is. First of all, He never sent anyone to hell for eating certain foods. Secondly He is holy and we are not. But He didn't leave us in that lost condition-He sent His son to pay the price for our sins , and yes we all have sin. That sounds like a pretty loving God to me. Would you lay down your life for the wicked? Or even for anyone to save them? Yet, many will reject Him. The sad realization will come to those who reject Christ when they stand before God Almighty and explain why we didn't think we needed Jesus and we were a "good" person. His standards of holiness are way above ours and no sin will be allowed in His presence. I pray God wakes you up before it is too late. 

JasperJohns
JasperJohns

All this recent asteroid business reminds me of this novel I just read called THE MYOSHI EFFECT which is about an asteroid headed toward earth and how everybody reacts and the government tries to find a way to deflect it. Granted the novel is humorous, like Dr Strangelove or Douglas Adams or something, but how we just reacted to these last 2 space rocks is almost taken from the pages of the book. Fiction and fact are fast becoming one.

raypeterson30
raypeterson30

Asteroids is gonna keill us awl faster than 9/11

luissaavedra
luissaavedra

It's "Arecibo" telescope not "Aricebo" ;)

anonymitty
anonymitty

Wrong about light pressure, Mr. Kluger. A bright, reflective surface will be pushed more by sunlight hitting it than a dark surface that absorbs the energy and then reradiates it. 


Asteroids spin. They don't turn any one face toward the sun. Energy that strikes the side of an asteroid that's facing the sun is like BBs hitting the asteroid, shot out from the sun. If it sticks, and then later pops off in a random direction, then only the initial impacts contribute to the overall momentum of the asteroid. The subsequent off-poppings cancel each other. But if the BBs  bounce back toward the sun, they count double. Overall momentum, as always, is conserved, but the BB's momentum wasn't just pretty well zeroed out, it was reversed.


Those toys with black and white panels inside a bulb demonstrating solar energy work because the dark panels are heated and the heat propels the bit of gas that's left in the bulb away from that side. It's a different phenomenon.

giuliano
giuliano

How can a destruction footprint be 2.150 square kilometeres if the radius of the circle is 23.2 Km? according to my geometry, that would give a 1.690 square kilometer circle

rocknrobert
rocknrobert

Google Planet X. As it comes near us every 3600 years or so, it is large enought to affect the path of asteroids and even our magnetic fields.

FredTurtle86
FredTurtle86

The Arecibo** Observatory in Puerto Rico; not "Aricebo". :)

VincentWolf
VincentWolf

There is a big dinosaur killer asteroid somewhere out there with our name on it you can be sure of that.  And it won't matter what it's trajectory is once it's here that's it were history.  Man does not have the capability right now of deflecting a 6 mile wide meteor.  We don't have have the capability of deflecting a 100 foot meteor because we don't have our heads in the right place.

JuliusRobinson
JuliusRobinson

Here is the ultimate irony, if that rock had missed 65 million years ago, we wouldn't be here. Something else, smarter, dumber, but not us. 

lafikdadi
lafikdadi

Let it be known that second coming of the Son will be likewise; in a second everything we will be doing will just come to a perpetual end and will be no more

RodVenger
RodVenger

This is an incredibly nonsensical and irresponsible bit of journalism. Some scientists have done some extrapolations to come up with the Tunguska data...it's size, mass, speed and height, but change any of those (be incorrect) and the rest of them must change as well. Further, NASA cannot even say with certainty where a satellite that they are guiding will come down. They guide it down into the atmosphere where physics says it will likely land somewhere in the pacific, but that's the best they can do. Not all re-entries are created equal and if a satellite starts to tumble, everything changes. So, we can do away with the notion that NASA or anyone else could say with certainty that a rock is going to come down and detonate over NYC. Not going to happen. At best it's one set of thousands of possibles. They can know the trajectory and entry point a few minutes before entry...they can tell us the path it will take, but that can change depending on the shape of the rock as well as it's angle. Even a rock entering straight down at a 90 degree angle to NYC would not necessarily continue on that path. A flat surface facing downward, versus a rounded or angled one, could easily cause the rock to tack north or south, east or west. You're going to evacuate NYC days or weeks ahead of a hit only to have that rock change direction inside the atmosphere and then impact the evacuees in some spot 100 or 500 miles away? Smart move, eh? The thing could have been weakened over the millenia and could bust up long before it hit earth, splitting into dozens or hundreds of chunks, shotgunning the entire Northeast with surviving chunks. Or those chunks could in turn redetonate over and over over a few second time and nothing survives to hit the ground. The whole thing could survive and slam into the ocean in which case the whole NE seaboard could be awash with tsunamis, or it could splash down a thousand miles out to sea and jeopardize the entire Atlantic...fish, crustaceans, mammals, plus the landborn people and animals on all affected coastlines all the way out to Africa...all wiped out by the waterborne shockwave and tsunamis. Fact is...it's not possible to "prepare" for a land event since its not possible to actually predict one with any certainty. The article serves only to make people nervous about the what-ifs and also to pry money loose from governments world wide for asteroid watching. That's already big news, with chicken little's all over the world screaming that we have to do something. This "once-in-100-year event" is only being called that because someone did the math between this event and the Tunguska event...but did they look back to the previous 100 years and the 100 years previous to that? You'd need at least 500 years of data, possibly more, to accurately label this a once in a 100 year event...another could hit tomorrow for all we know, and now that I think about it, we've seen some pretty big rocks fly overhead in the atmosphere just in our lifetimes. I can think of 2 that I have seen myself, whoppers, both. Only their angle kept them from being destructive, both came in, flew through, and kept on going. The sky may or may not be falling, but even if it is, we are in no position to responsibly evacuate ANYONE from ANY spot on the planet since we are just as likely to move them into the margin of error created by an irregular object coming into a thick atmosphere from space. Ask any mortorman or artillery officer about that margin of error. Sometimes, you do more damage than good just by trying to do good.

Dreiah
Dreiah

A recently published book called "Comets and the Horns of Moses" does a great job of explaining the history of comets and asteroids and their interaction with our planet. The book also provides evidence that major impact events are by no means "rare" in human history. It's a 'must read' for those who want to get up to speed on this increasingly important topic. Your life, or the life of a loved one, could depend on it!

Truth786
Truth786

These are the drones from Almighty. USA, please stop the drones on innocents otherwise, there is one that is suffice to eat the innocents in US also..

Ephesians618
Ephesians618

Seems Familiar:

But the day of the Lord will come like a thief, and then the heavens will pass away with a roar, and the heavenly bodies will be burned up and dissolved, and the earth and the works that are done on it will be exposed. Since all these things are thus to be dissolved, what sort of people ought you to be in lives of holiness and godliness, waiting for and hastening the coming of the day of God, because of which the heavens will be set on fire and dissolved, and the heavenly bodies will melt as they burn! But according to his promise we are waiting for new heavens and a new earth in which righteousness dwells. - 

2 Peter 3:10-13

The_Myth
The_Myth

How it will play out? It hits earth...that's how. 

ColinMarcus
ColinMarcus

"Solar energy becomes heat energy when it strikes an asteroid,  and that can exert a physical force all its own. A rock with a bright surface reflects more light away and feels less of an effect. A darker surface absorbs more and gets nudged more."

This is completely incorrect. It's actually the exact opposite - a perfectly black (absorbing) surface would simply absorb the photon momentum inelastically, giving a force F, but a perfectly reflecting surface interacts elastically - it reverses the photon's momentum, meaning it would experience a force 2F.

Shootist
Shootist

Time.com should of taken the time to speak with Jerry Pournelle or Larry Niven. I guarantee either one has thought more about this subject than anyone else Time could find.

nsbeer
nsbeer

Great article as always, with this incident in Russia today, lets hope the big rock does not hit us.

Follow my blog, as I link to space.com in which there is a live video feed on Asteroid 2012 DA14

https://nickbeerblog.wordpress.com/

25psot
25psot

In few hundred years humans will develop anti- asteroid missile systems that will protect our planet. But for now we can only pray

big asteroids will not reach Earth.

PlumbLine
PlumbLine

The Bible in Revelations warns us of a huge Asteroid that will hit earth during the Great Tribulation period that is coming........Turn from sin and Trust in Jesus today......He will come into your heart if you sincerely ask Him, by giving you the Holy Spirit and Eternal Life..

.........Revelation8: 8-11........8 The second angel blew his trumpet. Then something that looked like a big mountain burning with fire was thrown into the sea. And a third of the sea became blood. 9 And a third of the created beings in the sea died, and a third of the ships were destroyed. 10 Then the third angel sounded: And a great star fell from heaven, burning like a torch, and it fell on a third of the rivers and on the springs of water. 11 The name of the star is Wormwood. A third of the waters became wormwood, and many men died from the water, because it was made bitter.

CariJBennettDukes
CariJBennettDukes

except if you believe in the Bible, it clearly states Gods promise of never flooding the earth again.

VincentWolf
VincentWolf

What mankind needs to do is a concerted effort by all nations to TEST theories of deflection--using gravity traction, small nukes set off nearby to 'push' it a bit, etc. and try to ram the changed orbit of small to medium sized 'test asteroids' into the MOON.

Everyone can participate in this by enjoying the fireworks when it strikes the Moon which should be easily visible from space and even possibly change the smiley face were all so tired of.  

NASA just has no imagination instead focused on dead planets for no discernible benefit.


mikehaggag
mikehaggag

Just like the asteroid that killed the Dinosaurs, we need an asteroid that would kill roaches, rats, mice, and leave humans intact.

PaulPerry
PaulPerry

I think if the goal was to truly terrorize people with this article, they wouldn't have used NYC as ground zero.


Imagine the horror and terror they could generate if they predicted it was going to impact the Foxconn plant in China.

revwhitewolf
revwhitewolf

Pointless article.  How is writing about something that requires you to say "What if all of the details were different?" not just an exercise in fiction?

Could there be devastation from space?  Yes. The entire universe is actively trying to kill us.  Doesn't make it any more sensible to just pick one way that it might do it because this time around isn't the one.

BurtWay
BurtWay

What about the 1947 Sikhote-Alin iron meteorite that fell on the Sikhote-Alin Mountains in eastern Siberia? An estimated 70 tonnes of material survived the fiery passage through the atmosphere and reached the Earth. Tunguska in 1910 was not unique.  It is only in recent generations that we have learned what is happening.  A millenium ago, a local hisorian may have written, "A dragon came from the sky and destroyed the village."

whatsamatta_u
whatsamatta_u

That was a benign scenario.  Take it up a notch to the asteroid that likely hit us 65M years ago and you get a fireball that engulfs New York, spitting so much material into orbit to shroud the earth.  When that material falls back, the heat of reentry creates a global fire and temperatures that kill everything on the surface.  Then, comes the acid rain.  And then the remaining sulfur dioxide in the atmosphere brings on another ice age that can last up to 100,000 year.

In short, we really don't want this to happen.

Mr.Wallingford
Mr.Wallingford

This article doesn't answer the real question: Would Bruce Willis, Ben Affleck and their rag-tag team of drillers be able to save us in time? Or perhaps Robert Duval, John Favreau and their international crew?

spacelawpolicy
spacelawpolicy

A lot of what ifs.  Most media outlets are reporting on how 2012 DA14 is not going to be an issue for either the planet or satellites in medium-earth-orbit or GEO, but prognostications of doom makes better movies and "news" articles.  I see Time has opted for the latter.

jlee234
jlee234

I was just wondering everyone says it is going to miss Earth, but may knock out some of the satellites, is there any possibility of it getting knocked off its course due to the impact with satellites and hitting Earth? 

bhromine
bhromine

So to recap and sum up the science behind this article:  really big rock, blah blah blah, outer space, blah blah blah, hits earth, blah blah blah, it would be bad, blah blah. Right?


kenjdow
kenjdow

What a wasted article. Of course a bulls eye on NYC would be a catastrophe. But major metropolitan areas are exceedingly tiny and unlikely targets. What might actually be interesting an informative would be to read about the consequences of an impact in an unpopulated or lightly populated area or in the ocean, which together make up the vast majority of the earth's surface. In other words, if one of these things really does hit, what is actually likely to happen?