“A most dread portent took place, the sun gave forth its light without brightness.”

May 30, 2008 7:33 PM

The Atlantic has an interesting article about the high probability of "space rocks" hitting the earth, possibly as high as a 1 in 10 chance of a major catastrophe each century. Not a new theme, but the article has some new developments suggesting it is more common than once thought. Includes a 10 minute video.
posted by stbalbach (19 comments total)

Great article but how did no-one figure this out earlier? "We can tell from the craters we see about how often asteroids hit the Earth, no need to panic." "Tunguska didn't leave a crater." "Uh... well. OK, panic!"
posted by nicwolff at 7:58 PM on May 30, 2008

It was a very interesting article because it points out something quite obvious that doesn't get much play and hadn't occurred to many scientists until recently -- that the earth is covered 70 percent by water, and therefore there is evidence of much more undersea meteor, asteroid and comet strikes than previously thought.

It also hints that the great Biblical-era flood, recorded by several cultures and various geological evidence, may have been the result of such a water landing.
posted by Cool Papa Bell at 8:01 PM on May 30, 2008

There is something frustrating about living in the time where we are just smart enough to maybe see these things coming, but are totally incapable of doing anything to stop them.

For an asteroid-fear mongering article though, I have to give it credit for not once, (that I noticed), claiming that we are "due" for a cataclysmic asteroid event. The earth is not a significant sink in the universe for asteroids! There is no asteroid buildup around earth that increases the chance of asteroid strike. If you've lost the last 5 blackjack games, there's no higher probability of you winning the next one. Whether the probability is 1/100 or 1/1,000,000,000, it is that much from today on, whether or not an asteroid hit the earth yesterday does not matter. Sorry about that rant, but every other asteroid thing I've read or seen on TV has gambler's fallacy written all over it.
posted by SomeOneElse at 8:14 PM on May 30, 2008 [1 favorite]

A nice little article, although I haven't had time to read the third page yet. As far as I can tell it doesn't specifically mention yet another possible horror of 'space rocks', as illustrated quite nicely at Tunguska, Russia: the meteor or asteroid air burst. Even if a space rock does burn up before complete impact, it can still cause a good deal of damage. People have recently been trying to link this sort of thing to all kinds of mass extinction events.
posted by six-or-six-thirty at 8:40 PM on May 30, 2008

An idle thought:

In the kinetic theory of gases, as part of the formalism surrounding the ideal gas law, there's a method for finding the mean free path between scatterings for a single particle in the gas. This is used e.g. in the design of vacuum systems. While the gas is dense enough that the distance between collisions is short, it acts like a fluid; when the mean free path starts to be larger than your vacuum chamber, individual gas molecules go from wall to wall like billiards and you have to use a different sort of pump.

You could do the same thing with the solar system. The earth's orbit, integrated over some time, occupies some (tiny) fraction of the volume of the inner solar system. We know the masses and orbits of enough asteroids to make some statistical statement about the volume they occupy integrated over the same time period. This is enough information to make some statement about the mean time between collisions, which you could compare the number of observed craters. Or, perhaps, you could use the observed number of craters to estimate the density distributions of different-sized asteroids in the region of the earth's orbit.

I have no idea whether this is actually what's done or not. Doing it sloppily might take an afternoon; doing it carefully might be a nice way to spend some of an undergraduate research fellowship.
posted by fantabulous timewaster at 9:15 PM on May 30, 2008

A nice video of a planet wrecking impact....
posted by Kronos_to_Earth at 9:38 PM on May 30, 2008

(Um, If you haven't seen it already. Just realized, it's been around a while....)
posted by Kronos_to_Earth at 10:00 PM on May 30, 2008

Normally I loathe Easterbrook, but he is outstanding when he writes on space. His 1980 piece on the US Space Shuttle was prescient (""Beam Me Out Of This Death Trap, Scotty" Washington Monthly, April 1980"). Interesting article, thanks.
posted by Auden at 10:04 PM on May 30, 2008

Could happen in 1,000,000 years, could happen in 100,000 years or it could happen . . . next month! dun dun dunnnnnnn!

I'm waiting for a good caldera volcano boom, or a big earthquake here on the east coast; we're long overdue for one. (Yellowstone, anyone?)
posted by exlotuseater at 10:38 PM on May 30, 2008

If a comet hits tonight, I'm sorry. I was engaging in morally questionable activities. Fallwellian logic would indicate potential disaster.
posted by kozad at 10:59 PM on May 30, 2008

I saw Russell Schweickart give a fascinating lecture about the B612 foundation a few years back. I remember thinking the probability of earth getting catastrophically hit in my lifetime was nothing to worry about. Then he said something about if you are wondering about the frequency of large objects in space getting hit by rocks, etc, just look at the moon. It's completely covered in craters. That you can see from earth. with a relatively crummy telescope. huh.
posted by culberjo at 11:25 PM on May 30, 2008

Wow, great video, Kronos. The idea of all life on Earth being wiped out instantaneously doesn't bother me much. If everyone who knows and cares about you is destroyed at the same time you are, then there's nobody to mourn for you.
posted by Kraftmatic Adjustable Cheese at 11:36 PM on May 30, 2008

culberjo, the Earth has three things that the moon does not: an atmosphere, erosion, and an active geology. The first stops most of the smaller craters, the last two get rid of the evidence of the larger ones. The moon, like the Earth, is around 4 billion years old, but unlike the Earth it shows its age with an old, pockmarked surface. Throw in the idea that meteor strikes were more common in the past than they are today (a 'sweeping up' effect), and it means that you cannot conclude anything about our current daily chance of an asteroid strike by looking at the moon.
posted by moonbiter at 2:39 AM on May 31, 2008

1 in 10 chance of a major catastrophe each century.

If it were this high, we would have to be extremely lucky to still be here after all these thousands of years.
posted by DU at 2:58 AM on May 31, 2008

moonbiter, my apologies as I paraphrased Schweickart's statement haphazardly. I believe his point was simply: craters on large objects in space are caused by something smashing into them. Obvious, I know, but it made me ponder.

He used other heavenly body examples, and had known NEO charts and lists of potentially hazardous asteroids to help define probability, but the (layman's) moon crater reference sunk in for me (=no math!). His foundation's goal is to prevent large objects from smashing into earth (or smashing into pieces just above the surface). They want to move an asteroid somehow. It was a fascinating lecture.
posted by culberjo at 7:34 AM on May 31, 2008

Interesting article, but I don't buy a Pacific tsunami as the source of flood myths in near Eastern culture. A tsunami, even a 200m one, would not drown all land across the whole surface of the Earth, and I doubt it would have a significant effect on the mythology of inland non-Pacific cultures like the Assyrians, Persians etc., even if you assume that Noah's Flood, Deucalion and Pyrrha etc. were all direct copies from Akkadian originals.
posted by athenian at 11:06 AM on May 31, 2008

The chance that a "dinosaur-killer" asteroid is headed this way is vanishingly small. The chance that a Sikhote-Alin sized item could strike the Earth (as actually happened in 1947) is much higher.

The Sikhote-Alin object dumped something like 100 tons of iron and crud onto a forest in the Soviet far east. If something like this hits in the middle of Siberia again, or the ocean, or the Sahara, not that big a deal. If it hits in a populated area, that's a very big deal, but the chance of that happening is much lower.

One thing people miss out on is what a small area of the Earth's surface is actually densely populated. Once you subtract out oceans, lakes, mountains, deserts, ice, forests, jungles, and general scrubland, the area you're left with is actually pretty small. Humans aren't that big a target.

Then there's the possibility or probability that large, even destructive items, could blow up in the atmosphere in a fiery airburst, locally destructive, but leaving little or no crater on the ground. This is one idea about what happened at Tunguska. If the Tunguska event had happened in the middle of the ocean, we might never have known that it even happened.

The ability for people to monitor the whole planet for such events has only been around since the 60s or 70s, and for part of that time some of those capabilities were classified. It's very possible that potentially destructive objects have been striking no a fairly regular basis (I've heard a guess of "one Tunguska per century"), it's just that before modern satellites, and certainly before the explorations of the last 400 to 500 years, news of them wouldn't have travelled or would have gone unnoticed.

Now that we can monitor the whole planet and atmosphere from satellites, we probably will notice more events, fireballs, what have you. Compare this one, that just happened in 2002 over the Mediterranean, and had maybe twice the explosive power of the Hiroshima bomb.

Executive summary: the big ones are too rare to worry about, the little ones will just burn up, it's the ones in the middle that are worth concerning yourself with.

(I haven't read *this* article yet, I still have the paper copy of the magazine around the house waiting for me.)
posted by gimonca at 12:23 PM on May 31, 2008

I haven't read this Atlantic article yet, but I recall reading a lengthly article on this topic in the New Yorker about 10 years ago. This has prompted me to finally install my Complete New Yorker hard drive that I bought a year ago. The article is "Annals of Space--Is This the End?" by Timothy Ferris, 27 January 1997.

Abstract: "About the possibility of a comet strike or meteor strike destroying life on Earth... It came to pass one dark night in 1994 that Edward Teller, known as "the father of the hydrogen bomb," found himself in the front seat of a bus speeding down a remote highway east of the Urals, his face illuminated by the flashing blue lights of a police escort, on his way to the Russian Federal Nuclear Center at Snezhinsk, better known as Chelyabinsk-70. The scientists and engineers at Chelyabinsk-70 are experts in the design and manufacture of nuclear weapons, missiles, and tracking systems... Tells about his plan for a nuclear asteroid and comet-deflection system.... As he said, soon after the Chelyabinsk meeting, "we are very sick, I have a cure, and my only concern is to achieve overkill." Other scientists have been quick to object to Teller's injecting nuclear weapons into the previously pacific field of asteroid research, and Teller soon retreated to the position that conventional explosives could do the job. But by that time he was deeply embroiled in a debate with several researchers, Carl Sagan among them, who feared that even a non-nuclear "cure" would be worse than the disease. Clark Chapman, an astronomer of the Southwest Research Institute in Boulder, Colorado, denounced Teller's proposals as "radically more expensive and dangerous than the modest threat they would address." .. Teller is arguably the least popular eminent physicist in America. Teller is director emeritus of the Lawrence Livermore National Laboratory. Born in Budapest in 1908, he obtained his Ph.D. in Leipzig and fled Germany when Hitler came to power. He worked on the Manhattan Project and, after the war, pressed for development of the hydrogen bomb. During the McCarthy era, Teller testified concerning J. Robert Oppenheimer, who had reservations about the H-bomb. Teller portrayed Oppenheimer to the F.B.I. as left-leaning and expressed doubts about him in the Atomic Energy Commission hearings that resulted in the revocation of Oppenheimer's security clearance. Many physicists have forgiven Teller neither for what they see as his betrayal of Oppenheimer nor for his devotion to secret weapons research. Writer interviews him at the Hoover Institution, at Stanford University."

Now to read some old George W. S. Trow (271 results!).
posted by neuron at 2:05 PM on June 1, 2008

This was a good article, but I have to disagree with the author ribbing on the renewed moon program as a waste of money. If the continued survival of the human race is the primary goal here, then getting all our eggs out of the same planetary basket is one of the surest ways to achieve said goal.
posted by Veteran4Peace at 9:12 PM on June 2, 2008