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Asteroid Impacts Bigger Risk Than Thought

Unknown Lamer posted about 3 months ago | from the just-build-space-lasers dept.

Space 172

Rambo Tribble (1273454) writes "The B612 Foundation, a U.S.-based nuclear test monitoring group, has disclosed that their acoustic sensors show asteroid impacts to be much more common than previously thought. Between 2000 and 2013 their infrasound system detected 26 major explosions due to asteroid strikes. The impacts were gauged at energies of 1 to 600 kilotons, compared to 45 kilotons for 1945 Hiroshima bomb."

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*cracks open colleagues head... (-1, Offtopic)

bazmail (764941) | about 3 months ago | (#46824375)

....and feasts on the goo inside.....*

Am I reading this right (2, Interesting)

Anonymous Coward | about 3 months ago | (#46824417)

Between 2000 and 2013 their infrasound system detected 26 major explosions due to asteroid strikes. The impacts were gauged at energies of 1 to 600 kilotons, compared to 45 kilotons for 1945 Hiroshima bomb.

Is the Earth basically getting nuked (in terms of explosive yield) about twice per year without anybody noticing?

Re:Am I reading this right (1)

tomhath (637240) | about 3 months ago | (#46824457)

I'm pretty sure the people in Russia noticed that one last year. But yea, when it releases that energy high in the atmosphere it doesn't usually do any damage on the ground. Plus about 70% of the time it happens over an ocean.

Re:Am I reading this right (4, Insightful)

beelsebob (529313) | about 3 months ago | (#46824527)

70% of the time over the ocean, 99.99% of the time over somewhere that isn't populated. It's a 1 in 10,000 occurrence that this happens over a populated area. Given a rate of 2 a year, that means once every 5000 years on average, and many of these will not do any damage. So I'd say this is pretty much pure hype.

Re:Am I reading this right (4, Informative)

MozeeToby (1163751) | about 3 months ago | (#46824609)

About 3% of the planets land area is considered "urban". Taking into account the oceans that makes for right around 1% of the total surface area of the planet. That means that any given year there's about a 2% chance of an asteroid explosion happening over a major population area. That means a 1/3 chance of a significant (greater than 1 kiloton) explosion over an urban area over a 50 year time span. That's not crazy high, and most of those will occur at high altitudes, but it's certainly not once in 5000 years.

Re:Am I reading this right (4, Informative)

ThreeKelvin (2024342) | about 3 months ago | (#46824907)

Your math is off. If your numbers are correct, the risk of having at least one meteor over an urban area during those 50 years is:

P(N>1) = 1-P(N=0) = 1-(1-0.3*0.03)^100 = 60%

Re:Am I reading this right (0)

Anonymous Coward | about 3 months ago | (#46825373)

Many of the explosions they listed in the last 13 years WERE over urban areas. They were just so high over that it didn't matter (the worst effect was broken windows, if we don't count human panic). B612 is extrapolating the likelihood an ACTUAL IMPACT based on 13 years of zero impacts (but 26 atmospheric explosions). Whatever their math is, it's not this trivial, and probably very prone to error and low confidence.

Re:Am I reading this right (0)

Anonymous Coward | about 3 months ago | (#46826821)

My math isn't very strong; can you explain the (1-0.3*0.03)^10 part?

Re:Am I reading this right (0)

Anonymous Coward | about 3 months ago | (#46825055)

significant (greater than 1 kiloton) explosion
 
Not to come off as rude but can you point out the source of the metric that you're using as "significant"? It just doesn't seem that 1 kiloton at a couple dozen miles straight up is significant to anyone aside from those monitoring the activity.

Garbage in, garbage out. (0)

Anonymous Coward | about 3 months ago | (#46825555)

Yet there has never been one in recorded history.

Re:Am I reading this right (1)

Dasher42 (514179) | about 3 months ago | (#46825653)

I would say that the tsunami that would result from an ocean impact would be broadly devastating, and damage a large number of dense urban areas. How much of the ocean's surface area is a serious risk, would you say?

Re:Am I reading this right (1)

rubycodez (864176) | about 3 months ago | (#46826079)

no, these energies we're talking about are PUNY compared to those that make disasterous tsnunamis, like the 2011 one 480 METAtons of energy

Re:Am I reading this right (1)

rubycodez (864176) | about 3 months ago | (#46826093)

hah, mega not meta.

Re:Am I reading this right (1)

OhSoLaMeow (2536022) | about 3 months ago | (#46826717)

hah, mega not meta.

You must work for the NSA. An honest mistake.

Re:Am I reading this right (0)

Anonymous Coward | about 3 months ago | (#46824901)

99.99% of the time over somewhere that isn't populated

That isn't something that should be talked about. There are too many people on this planet on only the stupid Republicans are incapable of understanding that. Pointing-out facts like that only support their misunderstanding of science so they should not be discussed.

Re:Am I reading this right (0)

Anonymous Coward | about 3 months ago | (#46827303)

Same stupid troll post every time. What a moron.

cagw... (0)

harvey the nerd (582806) | about 3 months ago | (#46825479)

...hype is running out of steam. Now we'll see used meteor shield salesmen in academia looking for govt tit and power.

Re:cagw... (0)

Anonymous Coward | about 3 months ago | (#46825565)

Diamondium is the future!

Re:Am I reading this right (1)

OneAhead (1495535) | about 3 months ago | (#46825545)

Congratulations on your first post. That is, first rational post in this thread. Also, I wonder if nobody noticed:
- the scientific community has known this for a long time
- the solution proposed by this fine shill^H^H^H^H^Hnonprofit organization is a specific commercial product [wikipedia.org] by a company it has connections with [ballaerospace.com] ?

Re:Am I reading this right (0)

dpilot (134227) | about 3 months ago | (#46825785)

You could look at them as shills, or you could look at them as putting their money where their mouths are. The saw a threat and are doing what they can within our system to handle it.

So when government does it, it's either inefficient or a boondoggle, but when a company does it, attempting to inform about the threat they're trying to solve makes them a shill. As long as they're above-board about their position, and clear and honest with their science, I see no problem.

Re:Am I reading this right (1)

OneAhead (1495535) | about 3 months ago | (#46826917)

You should read my post as well as the post I replied to again. There is not threat to speak of; this is FUD. Also, they're neither clear - they haven't released raw data - nor perfectly honest - the scientific community has long been aware of the time and energy distribution of these strikes, so "bigger than thought" is dishonest [slashdot.org] and it really should have been "bigger than appreciated by the general public".

Re:Am I reading this right (1)

Anonymous Coward | about 3 months ago | (#46824697)

Not to mention that the one in Russia was on the high end of that range at 500 kilo tons [spacesafetymagazine.com] .
 
As an amateur astronomer I've seen a couple dozen fireballs in my time, some ending pretty wildly. I'm wondering how many of those come in at the 1-10 kilo ton range. To be frank it almost sees like 1 kilo ton airbursts would be a joke at the height that most of these objects seem to go kablooie at.

Re:Am I reading this right (2)

benjfowler (239527) | about 3 months ago | (#46824787)

The Chelyabinsk meteorite strike certainly hurt a lot of people. A few thousand ended up in hospital, mostly from projectile injuries, but a few also with burnt skin and retinas (the fireball was briefly several times brighter than the Sun).

Re:Am I reading this right (1)

someone1234 (830754) | about 3 months ago | (#46824523)

You can explode 600 kilotons every year without anyone but satelites noticing.

Re:Am I reading this right (1)

ackthpt (218170) | about 3 months ago | (#46824615)

You can explode 600 kilotons every year without anyone but satelites noticing.

I see them, now and then, during the daylight hours, but you have to be looking up and in the right area to spot them. Some are pretty exciting to see.

Re:Am I reading this right (1)

phantomfive (622387) | about 3 months ago | (#46824887)

Are you looking at the sun?

Re:Am I reading this right (0)

Anonymous Coward | about 3 months ago | (#46826049)

Are you looking at the sun?

I don't think he can tell anymore....

Keyword: BLIND

Re:Am I reading this right (1)

geogob (569250) | about 3 months ago | (#46824625)

That's bound to happen when those who can notice are found in less than 75% of the the surface of the planet.

Re:Am I reading this right (2)

doconnor (134648) | about 3 months ago | (#46825127)

Once difference is that the energy is spread out over kilometers rather then all at one point near the surface.

This Quirks and Quarks story on the The Chelyabinsk Meteor [www.cbc.ca] talks about this and how the data suggests impacts are more common then we thought.

Re:Am I reading this right (yes and no) (2)

ZahrGnosis (66741) | about 3 months ago | (#46825347)

No. The B612 people's math is demonstrably wrong, or at least very misleading.

26 explosions happened in the atmosphere in the last 13 years. Some of them broke windows but none had significant impact on cities, and would not have no matter their location. I don't know how they predicted once every hundred years, but they're wrong for two reasons. First, predictive analytics just doesn't work that way with any high confidence. If I flip a coin -- one that I know is cheating -- 26 times and it comes up heads every time, what are the odds that it will come up tails? You don't know... You can't know. You can make some educated guesses, but there is no real confidence. In the case of these explosions I'm sure they can model the size, altitude, and some other things, but still, they can't really know this, and they seem to fail to account for things like the impact of jupiter and the moon and sun on larger asteroids (which does actually affect the math). Second, you can compare the numbers to recorded history. The earth has certainly been hit by asteroids that would destroy a city. The last one probably happened off the coast of New Zealand around 1400 BC and caused a tsunami wiping out some local villages. There are only a few hundred noteworthy craters on earth over the past few hundred-million-years. That works out to "not one per century".

Make no mistake -- I think we should prepare for and defend against them, and I'm in favor of the satellite and conversation on the topic. But the numbers in this study are difficult to swallow and I accuse the hopefully well-intentioned people behind B612 of some under-founded alarmism.

Re:Am I reading this right (0)

Anonymous Coward | about 3 months ago | (#46827059)

Better watch out with this publicity and freedom thingy. The NK, or some other evilisish nation may get a hint and build a horrible nukular device, sounding just like an asteroid impact.

Severe error in summary (2, Informative)

Anonymous Coward | about 3 months ago | (#46824427)

The B612 Foundation [b612foundation.org] is a private venture dedicated to finding NEOs that will impact the Earth. They used nuclear test monitoring equipment to find the explosions resulting from asteroid impacts.

Re:Severe error in summary (3, Interesting)

rossdee (243626) | about 3 months ago | (#46824547)

Maybe some of those events were earthquakes. I find it hard to believe that their were 26 major impacts that we didn't know about. 600KT is hard to miss even if it is in a remote area.

Re:Severe error in summary (2)

mveloso (325617) | about 3 months ago | (#46824777)

According to B612 they were all airbursts. I wish they'd make their data public, so people could take a look and see.

Re:Severe error in summary (1)

Tablizer (95088) | about 3 months ago | (#46827223)

They could be UFO's popping in from another dimension. All joking aside, I wonder if the data actually points to meteors or just a general disturbance because otherwise the disturbances could be some unknown phenomena.

Re:Severe error in summary (0, Troll)

Squidlips (1206004) | about 3 months ago | (#46825041)

So the greater the threat, the more funding they get so the results are not too surprising.

How much energy? (1)

BobMcD (601576) | about 3 months ago | (#46824443)

If our planet is absorbing these impacts, and therefore converting the potential energy into something else, what's the (previously-unmeasured) impact of that?

For example, what if that energy became heat?

Re:How much energy? (0)

Anonymous Coward | about 3 months ago | (#46824513)

This is picky but I think you meant to say kinetic energy.

Re:How much energy? (1, Informative)

Anonymous Coward | about 3 months ago | (#46824537)

Not a lot. While 600kilotons of TNT on a local scale is an enormous amount of energy. That amount of energy spread over the world as heat is almost unmeasureable especially compared to other more major factors such as global warming.

Re:How much energy? (0)

Anonymous Coward | about 3 months ago | (#46824587)

Not a lot. While 600kilotons of TNT on a local scale is an enormous amount of energy. That amount of energy spread over the world as heat is almost unmeasureable especially compared to other more major factors such as global warming.

It's climate change now. Get with the program Al Gore.

Re:How much energy? (3, Informative)

by (1706743) (1706744) | about 3 months ago | (#46824661)

600 kilotons TNT is about 2.5e15 J. In comparison, the sunlight incident on the Earth is around 174 petawatts, meaning it takes roughly 20 milliseconds for that much solar energy to be absorbed (clouds, oceans and land masses) by the Earth (taking into account the ~30% reflected power). In comparison, the total world annual energy consumption is around 5e20 J. So, I wouldn't be too worried about added heat due to asteroids.

Sources:
https://www.google.com/search?... [google.com]
http://en.wikipedia.org/wiki/O... [wikipedia.org]
http://en.wikipedia.org/wiki/S... [wikipedia.org]

Re:How much energy? (1)

blackanvil (1147329) | about 3 months ago | (#46827569)

Unlike a nuclear weapon, meteors don't go boom at a planned optimal height to cause damage, and release their energy in stages. The Chelyabinsk meteor, for example, is estimated to have had the equivalent of a 500 kiloton nuke in terms of energy when it first entered. It weighed an estimated 12,000–13,000 metric tonnes and was moving at about 30km/s before it hit atmosphere, but the largest piece recovered was only some 654 kg, and most smaller pieces of the meteor hit the earth at terminal velocity after breaking up some 23km above the surface. Wikipedia says that some ~90 kilotons of energy equivalent was lost as heat as it entered, the rest in a series of 3 explosions as it broke up, the largest initial blast mostly being absorbed by the atmosphere.

Re:How much energy? (2)

ganjadude (952775) | about 3 months ago | (#46824677)

blame the asteroids for global warming!

Re:How much energy? (1)

Anonymous Coward | about 3 months ago | (#46825475)

No, blame the asteroids on global warming.

Re:How much energy? (1)

MozeeToby (1163751) | about 3 months ago | (#46824759)

I doubt it's significant but hey, math is fun so here we go!

They don't really say what the distribution of the impacts was at least not in a way that's easily accessed, statistically it's likely to be mostly smaller impacts but like I said, I doubt the answer will be significant so lets do an absolute worst case of 2 600 kiloton events every year. That makes 1200000 tons of TNT worth of energy every year. Google tells me 1 ton of TNT is equal to 4.18 gigajoules of energy so that comes out to 5*10^15 joules per year. That comes out to 1.4 megawatt hours. While large, it pales in comparison to the 143,000,000,000 megawatt hours that the human race uses every year (which in turn pales in comparison to the amount of energy the sun puts into the planet every year)

Happy Hump Day From The Golden Girls! (-1)

Anonymous Coward | about 3 months ago | (#46824453)

Thank you for being a friend
Traveled down the road and back again
Your heart is true, you're a pal and a cosmonaut.

And if you threw a party
Invited everyone you knew
You would see the biggest gift would be from me
And the card attached would say, thank you for being a friend.

Re:Happy Hump Day From The Golden Girls! (-1)

Anonymous Coward | about 3 months ago | (#46824671)

You're losing your touch. Fifth post. It's like you're getting into your golden years.

1-600 kilotons (5, Informative)

Arancaytar (966377) | about 3 months ago | (#46824455)

8/25/2000 (1-10 kilotons) NORTH PACIFIC OCEAN
4/23/2001 (1-10 kilotons) NORTH PACIFIC OCEAN
3/9/2002 (1-10 kilotons) NORTH PACIFIC OCEAN
8/9/2006 (1-10 kilotons) INDIAN OCEAN
9/2/2006 (1-10 kilotons) INDIAN OCEAN
10/2/2006 (1-10 kilotons) ARABIAN SEA
12/9/2006 (10-20 kilotons) EGYPT
9/22/2007 (1-10 kilotons) INDIAN OCEAN
12/26/2007 (1-10 kilotons) SOUTH PACIFIC OCEAN
10/7/2008 (1-10 kilotons) SUDAN
10/8/2009 (>20 kilotons) SOUTH SULAWESI, INDONESIA
9/3/2010 (10-20 kilotons) SOUTH PACIFIC OCEAN
12/25/2010 (1-10 kilotons) TASMAN SEA
4/22/2012 (1-10 kilotons) CALIFORNIA, USA
2/15/2013 (>20 kilotons) CHELYABINSK, OBLAST, RUSSIA
4/21/2013 (1-10 kilotons) SANTIAGO DEL ESTERO, ARGENTINA
4/30/2013 (10-20 kilotons) NORTH ATLANTIC OCEAN

yyeeeah, those are technically all between 1-600 kilotons.

Also, between 1 kiloton and 600 gigatons.

Re:1-600 kilotons (1)

Jack9 (11421) | about 3 months ago | (#46824501)

Nothing landed at 600 kilotons. That event would have been noticed, so I'm not sure about the purpose of the hyperbole.

Re:1-600 kilotons (4, Funny)

CanHasDIY (1672858) | about 3 months ago | (#46824689)

Nothing landed at 600 kilotons. That event would have been noticed, so I'm not sure about the purpose of the hyperbole.

Between 1 and 7,000,000 people who read OP's post got the point.

Re:1-600 kilotons (1)

OneAhead (1495535) | about 3 months ago | (#46825569)

I'm not sure about the purpose of the hyperbole.

Oooh I know that one: making money [ballaerospace.com] .

Re:1-600 kilotons (0)

Tokolosh (1256448) | about 3 months ago | (#46826149)

It has been determined that the required levels of population scaredyness are not being attained by Global Warming (TM). To make up the deficit, the possibility of imminent random annihilation must (literally) hang over the heads of the public.

Re:1-600 kilotons (0)

Anonymous Coward | about 3 months ago | (#46826749)

Hyperbole is like vitamin C for Space Nutters. They need it every day or else they get sick.

Re:1-600 kilotons (-1)

Anonymous Coward | about 3 months ago | (#46824539)

Holly shit, they are all between 1 kiloton and 30 billion kiloton. We are pretty much done for.

Re:1-600 kilotons (4, Interesting)

darkshot117 (1288328) | about 3 months ago | (#46824899)

I'm not sure why that data cuts off at ">20 kilotons", which seems to hide the fact that Chelyabinsk was measured to be 400-500 kilotons. >20 seems to be a bit of an understatement here.

Re:1-600 kilotons (1)

mdsolar (1045926) | about 3 months ago | (#46825893)

Perhaps it is detector saturation.

Re:1-600 kilotons (1)

hAckz0r (989977) | about 3 months ago | (#46825267)

Yes, and the story line would have been a lot different if they had just come out and said that only two were greater than 20 kilotons. Now compare that fact with the statement "Hiroshima was a 15-kiloton device" to put things more in perspective. Granted, you don't want one falling on your city, but it isn't going to kill millions more with deadly radiation after the impact either. Its the aftermath of the A-bomb that was so gruesome. Until the asteroid gets big enough to create a 'nuclear winter' the risk to humanity in general is fairly small.

Not impressed (2, Informative)

Anonymous Coward | about 3 months ago | (#46824493)

First, the Hiroshima bomb was 13 Kilotons, not 45. Nagasaki was roughly 20 Kilotons.

Re:Not impressed (2)

peon_a-z,A-Z,0-9$_+! (2743031) | about 3 months ago | (#46824567)

Being "picky" on your "pickiness", I'll say it was instead 16 Kilotons and provide a citation!

http://en.wikipedia.org/wiki/L... [wikipedia.org]

Re:Not impressed (0)

fnj (64210) | about 3 months ago | (#46824995)

One thing NOBODY who is the least bit informed thinks is that it was 45 kT.

Body: asteroid strikes more common than thought (1, Funny)

kruach aum (1934852) | about 3 months ago | (#46824515)

Headline: asteroid strikes bigger risk than thought.

If I find a magic lamp one day the first thing I'm wishing for is not rustproof +2 grey dragon scale-mail but the removal from existence of click-bait. Hint: "asteroid strikes more common than thought" would have been interesting enough to get me here, morons.

Re:Body: asteroid strikes more common than thought (2)

OneAhead (1495535) | about 3 months ago | (#46825469)

"asteroid strikes more common than thought" would have been interesting enough to get me here

...but it would still be dishonest and I would still take offense. "...more than thought" implicitly implies "...more than the scientific community knew about". This is false. Nothing in this story suggests that science was not aware of this frequency. An honest headline would be "frequency of asteroid strikes underappreciated by the general public". Which doesn't say all that much [slashdot.org] . Also, as pointed out elsewhere in this thread [slashdot.org] , the risk of large-scale loss of life is minimal. This is all fear-mongering to get a [wikipedia.org] product [ballaerospace.com] sold. It's a bit scandalous how media fall over themselves to repost this non-story without the smallest amount of background research. BBC is this close to losing its status as my primary news source.

risk (1)

phantomfive (622387) | about 3 months ago | (#46824517)

I don't think the word 'risk' means what they think. If no one is noticing, it doesn't seem like there's much risk

Re:risk (4, Insightful)

almitydave (2452422) | about 3 months ago | (#46824811)

Right - if we find out that these are happening much MORE often than previously thought, and yet damage is rare, then it seems like they're LESS of a risk than previously thought. Sort of like finding out that when you swim at the beach, sharks are close by more often than you realized - meaning the risk of them attacking you is lower. If anything this indicates that the Earth's natural asteroid defenses are more robust than previously realized.

Besides, I remember reading that kiloton-scale atmospheric asteroid detonations happened once every month or two, but this indicates it's less often than that, so they're actually LESS common than I thought. I could have misremembered that stat, though.

Re:risk (2)

OneAhead (1495535) | about 3 months ago | (#46825639)

The problem lies in their highly misleading use of the phrase "than previously thought". The scientific community has been aware of the time and energy distribution of these strikes for a long time. They actually meant "than appreciated by the general public". More on that here [slashdot.org] .

Bad comparison (1)

gurps_npc (621217) | about 3 months ago | (#46824627)

The asteroid impacts detected are almost all air bursts and they have no radiation. So almost no damage is being done. A better description would be to compare it to lightning strikes, not nuclear bombs.

It's not like we are getting city sized destruction on a regularly basis, it's like we are getting thunderstorm type events on a regularly basis.

The real danger would be for things signifcantly larger that hit ground, rather than the upper atmosphere.

Re:Bad comparison (1)

Whorhay (1319089) | about 3 months ago | (#46825597)

Impactors actually hitting the ground would definitely cause more damage. But air bursts can still be devastating enough. Tunguska was an air burst and it leveled something like 2,000 square Kilometers of forrest. Granted Tunguska was much larger than the asteroids in this report.

Those guys want pork funds too? (1)

Torp (199297) | about 3 months ago | (#46824651)

Like the US politician that was demanding 2 billion for protection from an EMP attack?

Re:Those guys want pork funds too? (1)

Sarius64 (880298) | about 3 months ago | (#46825045)

The tax breaks given to professional sports teams could have financed a complete space station surrounding Saturn with current technology, IMO. Stop giving billionaire gladiator owners tax breaks.

Re:Those guys want pork funds too? (1)

ultranova (717540) | about 3 months ago | (#46825287)

a complete space station surrounding Saturn

That's a pretty big space station. Maybe start with something smaller and more practical, like a train ramp connecting to orbital ring for Earth?

Re:Those guys want pork funds too? (1)

garyebickford (222422) | about 3 months ago | (#46825727)

Let's promote the installation of a 5G-capable magnetic launcher (coilgun tech) that goes up the Andes in Ecuador! A 50 mile launcher using a tube that is evacuated of most of its air could replace most or all of the first stage of rockets going to LEO, cutting the cost of launch by 2/3. The technology and project scale are in the same ballpark / order of magnitude as the LHC, and would permanently alter the economics of space development. The last time an equivalent system was thoroughly studied was in the 1970s AFAICT, long before a number of major enabling technologies were mature enough - large superconducting magnets, various materials, control systems, etc.

Re:Those guys want pork funds too? (1)

Sarius64 (880298) | about 3 months ago | (#46826715)

My example was in comparison to the hundreds of billions of dollars that have been given to billionaires so they would somehow not stop national sports teams from playing; which already make billions of dollars. Frankly, I'd take anything for a start. This ISS stuff is fairly pathetic compared to the things governments spend money on.

Bigger Risk Than Thought (1)

fche (36607) | about 3 months ago | (#46824657)

The pen may be mightier than the sword, but nothing is riskier than thought itself.

Re:Bigger Risk Than Thought (2)

garryknight (1190179) | about 3 months ago | (#46825243)

I came here to say something very much like this. Thanks for saving me the need to log in and... Oh, wait...

Wrong Number on Little Boy (4, Informative)

Shakrai (717556) | about 3 months ago | (#46824691)

Little Boy clocked in at ~15 kilotons, not 45 kilotons per TFS. Fat Man was ~21kilotons, though it was dropped off target and ended up doing less damage than Little Boy.

Re:Wrong Number on Little Boy (1)

DigiShaman (671371) | about 3 months ago | (#46825073)

Also less damage due to the hilly terrain surrounding Nagasaki.

Re:Wrong Number on Little Boy (1)

DerekLyons (302214) | about 3 months ago | (#46826479)

Fat Man didn't do less damage because it was dropped off target, it did less damage because the geography was different - the narrow valleys that Nagasaki was built in/around limited the spread of the blast wave and sheltered much of the city from the thermal effects.

Re:Wrong Number on Little Boy (1)

Shakrai (717556) | about 3 months ago | (#46827133)

From Wikipedia: At 11:01, a last-minute break in the clouds over Nagasaki allowed Bockscar's bombardier, Captain Kermit Beahan, to visually sight the target as ordered. The Fat Man weapon, containing a core of about 6.4 kg (14 lb) of plutonium, was dropped over the city's industrial valley at 32.77372N 129.86325E. It exploded 47 seconds later at 1,650 ft (503 m), ± 33 ft (10 m), above a tennis court halfway between the Mitsubishi Steel and Arms Works in the south and the Mitsubishi-Urakami Ordnance Works (Torpedo Works) in the north. This was nearly 3 km (1.9 mi) northwest of the planned hypocenter; the blast was confined to the Urakami Valley and a major portion of the city was protected by the intervening hills.

And yet ... (1)

pablo_max (626328) | about 3 months ago | (#46824883)

It seems that even though it could destroy a city every 100 years, in actual fact I has never happened in recorded history.
I am not saying we should not keep a look out, but I am pretty sure we can go to bed and still wake up without our city being a waste land.

Re:And yet ... (1)

ray-auch (454705) | about 3 months ago | (#46825247)

Does depend a little bit on which books you count as recorded history vs. fiction, and how you interpret the descriptions. E.g. "fire and sulphur rained from heaven" could be volcano - unless you believe the writers' culture would have known what a volcano was and would have said "from the mountain".

Re:And yet ... (1)

schlachter (862210) | about 3 months ago | (#46825791)

world wide recorded history is less than 500 yrs old.
there were hardly an cities in the world until about 100 yrs ago.
there were hardly any people in the world until about 10K yrs ago.
http://www.prb.org/Publication... [prb.org]

Re:And yet ... (1)

R3d M3rcury (871886) | about 3 months ago | (#46826061)

It seems that even though it could destroy a city every 100 years, in actual fact I has never happened in recorded history.

Sodom and Gomorrah? [universetoday.com] Also, keep in mind if this theory is accurate, this was an asteroid strike in the Alps that managed to wipe out a couple of cities in the middle east.

Re: And yet ... (0)

Anonymous Coward | about 3 months ago | (#46827181)

How about Atlantis? Maybe we should look again at those legends of cities destroyed by the gods, not only in Europe & the Middle East but around the world.

While it may be a slight risk, I think we should add it to our list of things to worry about.

Re:And yet ... (0)

Anonymous Coward | about 3 months ago | (#46826539)

There are many accounts of cities being destroyed by what could have been asteroid strikes. They're usually attributed to wrath of god(s) as they pre-date the field of astrophysics, and the accuracy of the claims is difficult to verify.

B612 Foundation Is An Asteroid Defence Group (2)

szyzyg (7313) | about 3 months ago | (#46824889)

They're nothing to do with nuclear test monitoring, they just happened to use data from the monitoring network to count the number of kiloton scale events in the last decade or so.

The B612 Foundation is a non profit organization trying to raise money for a asteroid discovery spacecraft, a telescope that will sit down near Venus's orbit and look outwards, enabling it to see asteroids near earth without the sun dazzling the optics (half the asteroids passing near earth are invisible because they are too close to the sun). It's not an unreasonable goal when you consider that high profile museums and educational institutions regularly raise hundreds of millions of dollars in donations.

Re:B612 Foundation Is An Asteroid Defence Group (0)

Anonymous Coward | about 3 months ago | (#46825583)

So... the more they scare people, the more money they raise. This explains some of their conclusions.

What increases the risk (2)

hansraj (458504) | about 3 months ago | (#46824935)

I don't think anyone is implying that we are doomed because of _these_ impacts.

However, in general the frequency of an impact event [wikipedia.org] is inversely proportional to the size of the impacting body. Smaller impacts happen more often than the larger ones. Counting the smaller ones precisely gives you an idea of what the risk of a big event is.

So far people underestimated these smaller ones that is being reported. The wikipedia article I linked to earlier, suggests one impact every five years at the level of 5 kT of TNT. These guys being right would imply a risk of at least a magnitude higher than previously estimated. That increases the risk for the really big ones too.

Re:What increases the risk (1)

R3d M3rcury (871886) | about 3 months ago | (#46826207)

I'm not sure I get this.

What I'm guessing is that the theory says that for every 1,000,000 grains of sand on the beach, there is one rock the size of your fist. There are 1,000,000,000 grains of sand, so there must be 1,000 rocks. What these guys are saying is that there are, in fact, 10,000,000,000 grains so there must be 10,000 rocks.

If I'm drawing the analogy correctly, I'm not sure I understand how they got the relationship between grains of sand and rocks and how they know that's accurate.

Re:What increases the risk (0)

Anonymous Coward | about 3 months ago | (#46827587)

You don't know! But you can still make an intelligent guess. There are uncertainties, but this suggests that the likely value is significantly higher than previously believed.

comets (2)

green is the enemy (3021751) | about 3 months ago | (#46825023)

The article authors say that most of the dangerous asteroids are already being tracked (additional tracking efforts under way), and can potentially be deflected since collisions can be predicted decades into the future. That's only a half-truth. Comets in the outer solar system are too dark to detect in their present locations, but can arrive at Earth very quickly. There will not be enough time to deflect them... Statistically, what percentage of impacts are from objects originating in the outer solar system? Is that even possible to determine?

This is the tail - it means more (3, Informative)

EngineeringStudent (3003337) | about 3 months ago | (#46825131)

We don't have enough history to gauge what actually has happened over time, so we have to estimate.
We approximate by finding big rocks or chemistry on earth, looking at craters on the moon, or this.

In all these cases we are using the small but frequent to infer the distribution of big but hugely problematic events. Our best answer the question about the likelihood of a killer impact is grossly changed if this tail is changed.

Think about it like floods. We ask how likely a 10,000 year flood is going to happen next year. We have ~100 years of rainfall data. We fit it to a distribution that is appropriate and then use those fit parameters to make a best guess. If our rain gauge was only measuring half the rain, we might under-estimate the actual risk by a factor of 10x or 20x.

There is good correlation between "killer impacts" and location of the sun in the galaxy (yes it moves around). We are starting to enter a higher risk region (transition to edge of arm) and perhaps the fundamental distribution is changing. In that case the history of craters on the moon or other might not be meaningful indicator of the near future.

Considering this I think good tracking is not a bad idea and should be thought out well and properly considered.

hmmm really.... (2)

Mr_Nitro (1174707) | about 3 months ago | (#46825141)

the whole solar system is covered with asteroid collisions..... shouldn't take a damn genius to get it's a real possibility to be hit by something a little too big to go unnoticed.... and the best solution ,as dear C.Sagan said, is to become a spacefaring race...the sooner we move our asses to mars (and beyond) the better.... it's our duty as a specie to at least colonize the solar system.... ...when they will stop laughing about it...

Re:hmmm really.... (1)

Blaskowicz (634489) | about 3 months ago | (#46825357)

Spacefaring ought to be postponed to the 22th century or late 21st.. We have more pressing things right now, mankind has yet to learn how to feed itself without destroying the land, rivers, climates and even the oceans.
When we'll be able to have many terawatts of clean power at home as well as decent energy storage (maybe make fuel out of water and air, or water and CO2 found in the oceans) then maybe we can dream about making shelter, food, air and water from moon or Mars materials.

Re:hmmm really.... (1)

Intrepid imaginaut (1970940) | about 3 months ago | (#46826083)

Solar microwave power satellites would provide all the clean energy you could wish for, but need a lot more orbital infrastructure before they can be deployed.

As for "destroying the land, rivers, climates and even the oceans", all of these remain merrily undestroyed. If you mean reducing the biodiversity around us you may have a point, but efforts are being made to preserve and protect as much as possible. Also, before we descend into a spiral of remorse a couple of points - protection of the biosphere and spacefaring are not mutually exclusive goals, in fact they are more complementary than anything else, and good old mother nature has been handing out mass extinctions like candy throughout the history of the planet without any help from people at all, so there's that.

I've not looked up in about 8 years. (0)

Anonymous Coward | about 3 months ago | (#46825159)

Of course we don't notice them we're too busy looking at our smart phones.

But, but, but Climate Change (0)

Anonymous Coward | about 3 months ago | (#46825209)

Nuclear bombs? Asteroid impacts? Acid Rain? Toxic Waste? Concealed Weapons?

No!

Global War ^h^h^h^h^h^h^h^h CLIMATE CHANGE is what is going to kill us all and that is all the media should report.

We should stop driving our cars and shut down all our factories in order to save the planet from melting.

B612? Just one away from.. (0)

Anonymous Coward | about 3 months ago | (#46825231)

Escandalo!

Article edited, please fix the summary.. (1)

Rick in China (2934527) | about 3 months ago | (#46825365)

Notice the article removed the ridiculous references implying that mega-hiroshimas happen all the time?

Risks are LESS than thought (1)

katorga (623930) | about 3 months ago | (#46826509)

In all of recorded human history, how many Cities, towns, villages, settlements or even individual humans have been directly killed by a meteor or asteroid impact?

The probability of being killed by a nuclear weapon is higher. This is simply a case of NASA creating some hype to justify continued budgets for a "space" agency that can't go to space any more.

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