It Came From Outer Space

July 19, Oxford, UK-Death by asteroids, comets and gamma ray bursts was on the agenda of the conference on Global Catastrophic Risks this morning. First up was NASA senior scientist David Morrison to talk about the Spaceguard Survey and the threat of a catastrophic asteroid strike. Morrison started out by noting that we had just past the centenary of the 5-15 megaton Tunguska airburst over Siberia. In 1998, Congress charged NASA with surveying the skies to detect 90 percent of near earth asteroids (NEAs) greater than 1 kilometer in size in 10 years. An impact by a kilometer-sized asteroid could end civilization. Besides the blast, such an asteroid would inject so much dust into the atmosphere that it would cause global winter that would cause massive crop failure.

According to Morrison, 80 percent of the NEAs that are a kilometer or more in size have been identified. Consequently, Morrison could happily assure the assembled Oxford catastrophe mavens, "We are not going the way of the dinosaurs." Why because the Spaceguard Survey has not turned up any NEAs near the size of the one that likely killed off the dinosaurs 65 million years ago. That asteroid measured between 10 and 15 kilometers and blasted the 180 kilometer-wide Chicxulub crater. Proposals to have the Spaceguard Survey expand to detect NEAs as small a 100-meters are now being considered. Morrison groused that NASA has spent only $ 4 million on Spaceguard and argued that the magnitude of the risk merits a budget of half a billion dolars.

Morrison pointed out that asteroid strikes are the only natural hazard that in principle can be completely eliminated. Thanks to the Spaceguard Survey, humanity will likely have decades of warning before an impending collision. Once alerted, missiles could be used to nudge a threatening asteroid so that it misses the earth. In this regard, Morrison cited an apt quotation from the poet Lord Byron:

"Who knows whether, when a comet shall approach this globe to destroy it, as it often has been and will be destroyed, men will not tear rocks from their foundations by means of steam, and hurl mountains, as the giants are said to have done, against the flaming mass? - And then we shall have traditions of Titans again, and of wars with Heaven."

But before becoming too complacent, keep an eye out for reports on the 210-330 meter asteroid Apophis-there's a 1 in 45,000 chance that it could hit the earth on April 13, 2036. Measurements in the next 3 to 4 years will determine just how big a chance of a collision there is.

Gamma Ray Bursts

Technion physicist Arnon Dar warned of another space hazard--gamma ray bursts (GRBs). GRBs were originally detected by U.S. military satellites that were checking to see if the Soviets were testing nuclear weapons. GRBs are beams of highly energetic photons produced when a gigantic star goes supernova. Dar described a GRB beam hitting the earth would be like a kiloton bomb per square kilometer going off at the top atmosphere. He speculated that some of the earlier mass extinctions, such as the Permian extinction in which perhaps 90 percent of all life died out might have been caused by GRBs.


So are there any stars likely to go supernova nearby? Dar pointed out that the gigantic star Eta Carinae at a distance of 7,500 light years has been extremely unstable of late. Eta Carinae is 100 times more massive than the sun and 5 million times brighter. When it goes it will be a hypernova. Dar then gave us the good news: Eta Carinae's axis is pointed away from the earth, so the GRB beam it will generate when it dies will be aimed far from us. However, don't get too complacent about GRBs. Future of Humanity Institute research fellow Anders Sandberg mentioned that some astronomers are worried that we may be looking down the barrel of gamma ray gun when the WR 104 binary located 8,000 light years away goes supernova.

Comets

If asteroids aren't likely to get us, maybe comets will. William Napier from the Center for Astrobiology at Cardiff University in Wales noted that long-period comets-those that originate in the Oort Cloud beyond Pluto-have generally been thought to constitute around 1 percent of the risk of catastrophic collision. Napier argues this is big underestimate. Napier's main concern is dark comets. Dark comets do not sport showy ejection tails like Halley's Comet does, but are much stealthier. Because they are dark, they are very hard to detect. Napier pointed out that the IRAS-Araki-Alcock comet was detected only two weeks before it came within 0.03 astronomical units of the earth (about 230 earth diameters) back in 1983-the closest of any known comet since 1770.

Napier argues that the record of large impact craters suggests that the earth experiences periods of cometary bombardment every 36 million years or so. He attributes the episodes to the sun's periodic passage through galactic plane where contact with molecular clouds dislodges comets from the Oort cloud surrounding the solar system. He believes that the earth is currently in a bombardment episode. "We have comet problem because they are hard to detect which means that we would have months or weeks of warning at most," said Napier.

Next up from the Oxford Global Catastrophic Risks conference are pandemics and nuclear war.

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  • Elemenope||

    SO, first we need to put Peter Stormare on a Russian satellite and give him a ridiculous accent.

    Then we need to find some compassionate sea-oil drillers.

    Then we need to build some bad-assed futuristic space shuttles. And get William Fichtner to pilot it and act like an asshole.

    Too complicated? Yeah, but as long as it's funny, we know the Earth is safe.

  • ||

    Comets hitting Earth are a walk in the park compared to what's gonna happen when they flip the switch on the new atom-smursher in Cern.

    Grab your ankles.
    I'm just sayin'...

    I give thanks to goddess I've already enjoyed existence longer than most of you. Existence has been velly, velly good to me.

    Ruthless

  • Don\'t forget...||

    ...lmnop, elvish princesses and a sound track from has-been rock stars

  • Elemenope||

    "...are you paying attention?! So that if I were to kick you in the balls here you'd know how to use the thrusters so as to not float away."

    "...DO NOT TOUCH my uncle. He's a very important man in Moscow. He built the thing on the top of the missile that finds, uh, New York, Los Angeles..."

  • Elemenope||

    Comets hitting Earth are a walk in the park compared to what's gonna happen when they flip the switch on the new atom-smursher in Cern.

    Grab your ankles.
    I'm just sayin'...


    Even with its badassery, most of what I've read indicates that a strangelet cascade or a black hole spontaneous formation are vanishingly improbable, if not impossible, over the lifetime of the accelerator.

  • ||

    also, we 'passed' the centenary

  • ||

    Elemenope,
    I don't care about the lifetime of the accelerator. I care about your life. And so does your mother.
    Did she ever say you are a party-pooper?

  • Elemenope||

    Elemenope,
    I don't care about the lifetime of the accelerator. I care about your life. And so does your mother.
    Did she ever say you are a party-pooper?


    Dood, I ams the Life of teh parties!

    Is this a partee?

  • ||

    Is this a partee?

    I think/hope it is, but I've been "bounced" in my day, so I'm not the Margaret Mead here.

  • TrappedEastOfTheBigMuddy||

    Elemenope @ July 19, 2008, 8:09pm


    Comets hitting Earth are a walk in the park compared to what's gonna happen when they flip the switch on the new atom-smursher in Cern.

    Grab your ankles.
    I'm just sayin'...



    Even with its badassery, most of what I've read indicates that a strangelet cascade or a black hole spontaneous formation are vanishingly improbable, if not impossible, over the lifetime of the accelerator.



    It goes much deeper than that. If any---any---of these disaster scenarios were possible, the Big Particle Accelerator in the Sky would have done for us long ago.

    Jesus christ on a pogo stick, the ultra-high energy cosmic ray people record multiple events every decade at 10^18+ eV.

    For those in the gallery, that is six orders of magnitude higher than the accelerator energies.

    It is a lot of fun to speculate about false vacuums and stable heavy-quark-matter states, but the universe has already done these experiments.

    Don't worry about it.

  • ||

    "Cuanto La Gusta" and it was originally sung by Carmen Miranda in the 1948 film "A Date With Judy".

    Tunguska airburst over Siberia.

    Coincidence?
    I think not...

    Trapped,
    Liquid excrement is running down my inner thigh.

  • Dave B.||

    It goes much deeper than that. If any---any---of these disaster scenarios were possible, the Big Particle Accelerator in the Sky would have done for us long ago.



    Planets are destroyed all the time by black holes and shit all over the universe. It just hasn't happened here yet. I don't think running the particle accelerator will result in a disaster scenario, but your argument isn't convincing.

  • ||

    Fortunately, the WorldGov has a plan for sudden near-earth black hole emergence.

    Everybody dies.

    They even have it underlined.

  • ||

    I'd rather die at the hands of some giant reptilian creatures invading the earth from a planet I can't pronounce. Then again, I like buttermilk.

  • ||

    Planets are destroyed all the time by black holes and shit all over the universe. It just hasn't happened here yet.

    Dave B.,

    By "big particle accelerator in the sky", he was literally referring to THE SKY i.e., these events have happened in Earth's upper atmosphere already, not far flung regions of the universe.

  • ||

    High energy cosmic rays have been striking the Earth since its inception. If the LHC were a threat, these cosmic rays would have done in the Earth a long time ago.

    Of course, I'm a physicist so maybe I'm willing to risk the Earth for an interesting result, and all of us (even those with families) are lying to you ...

  • ||

    Dave B.

    You may want to learn about high energy cosmic particle events that strike earth or its atmosphere. (hint, they're much more energetic than anything we can create now or in the forseeable future).

    Your odds:

    You have a better chance of being killed by a billiard ball sent flying from a New Jersey pool hall due to being hit by a brick knocked off of a russian building by a flight attendant who falls from a 737 nonstop flight from New York to Neptune powered by rodent farts.

  • ||

    This stuff about the large hadron collider reminds me of the biggest idiot on Youtube.

  • ||

    Bramblyspam,

    It's good to see that all the religious wackos don't come from just the US and Israel.

  • Kolohe||

    the biggest idiot on Youtube.

    This is quite an audacious claim; the competition is wicked fierce. Too bad I can't get youtube at work; I'll have to wait till later to judge for myself.

  • ||

    Quick question as to the Gamma Ray entry - If Eta Carinae goes hypernova (thank God the media didn't name it; we would have "super-duper" nova. Anyways, wouldn't the Gamma Ray Burst take 7500 years to get here, being 7500 light years away? Or is the instability that they are observing 7500 years old, and once we see the nova we'll be hit by the Gamma Rays?

  • The Ron Paul Astrophysical Rep||

    Napier's main concern is dark comets. Dark comets do not sport showy ejection tails like Halley's Comet does, but are much stealthier

    Well, at least he didn't call them 'black' comets. If he were part of the Dallas City Council he would be part of a Napier-headed row.

  • ||

    Here's the cool thing about Eta Carinae: when it goes hypernova it will be the brightest object in the sky apart from the sun for months. It will be brighter than the moon. It will essentially be like twilight for all the hours of the day the sun isn't up. It'll make policy responses to climate change look mild.

  • Metal Messiah||

    Quick question as to the Gamma Ray entry - If Eta Carinae goes hypernova, wouldn't the Gamma Ray Burst take 7500 years to get here, being 7500 light years away? Or is the instability that they are observing 7500 years old, and once we see the nova we'll be hit by the Gamma Rays?

    The latter. At 7500 light years away, the light that we're now seeing left the star 7500 years ago.

    So if the star already went nova 5000 years ago, we wouldn't know about it for another 2500 years.

    And also, yes, the gamma burst would travel at the same speed as light so it would hit at the same time we knew the star finally went kerblooey. It would basically happen without warning. Unless the star did something out of the ordinary before it novaed; which it might since we haven't, to my knowledge, observed something like this before.

  • ||

    "I'd rather die at the hands of some giant reptilian creatures"

    Reptilian creatures with hands!
    That is scary!

  • ||

    Wow, well written and makes prefect and logical sense. I always figured if the end came, it would be at the hands of something from outter space.

    JT
    http://www.Ultimate-Anonymity.com

  • Elemenope||

    Fortunately, the WorldGov has a plan for sudden near-earth black hole emergence.

    Everybody dies.

    They even have it underlined.


    While that is genuinely hilarious and all, I *am* going to be a party-pooper now and rain all over just how ridiculous a "near-Earth black hole emergence" scenario really is, not for it's likelihood but for it's threat-level.

    A mini Black-hole generated by proton collisions can have at best the mass of...two protons. The event horizon for such a hole would be on the order of a dozen angstroms across. It would probably evaporate in a heady burst of Hawking radiation before the singularity ever became incident with another piece of matter.

  • Ramsey||

    LMNOP, have to disagree with your science there. The black holes produced will have masses much greater than two protons, since the protons will have been accelerated to very near the speed of light. The faster something moves, the more it weighs, and since the instant the black hole forms all photons are trapped inside and energy cannot escape (except for Hawking Radiation, another story entirely and what will save the world if a black hole does form, but you knew that part already) the black hole will contain all of the energy released by the collision of these two artificially massive particles. Your estimate is off by a few orders of magnitude. Luckily a few orders of magnitude greater than almost nothing is still almost nothing.

  • Elemenope||

    Ramsey,

    I know they wouldn't be at rest mass, but even a proton moving at .90c isn't all that heavy. And that's the best case; far more likely is that most of the impact mass would be lost in a shower of quarks and mesons.

    The evaporation times for black holes that size is on the order of microseconds. Far too little time to go find itself an atomic nucleus to snack on.

  • Marilyn Terrell||

    An asteroid doesn't have to be 10 km wide to do a lot of damage. In 1908 an asteroid or small comet the size of a 15-story building exploded over a remote spot in Siberia called Tunguska, blowing down trees and scorching the earth within 800 square miles, according to this story in the August National Geographic, which also talks about plasma thrusters on gravity tractors to fend off future asteroids:
    http://ngm.nationalgeographic.com/2008/08/earth-scars/stone-text

  • ||

    LMNOP & Ramsey

    Based on the formula for the radius of a black hole, and assuming the accelerator gooses the proton mass up to around 10tev (approx 10 million times the rest mass), the black hole resulting from the collision of two such protons would have a diameter around 10^-46 meters.

    That's less than the Planck distance. The damn thing would evaporate by Hawking radiation within a femtosecond of being born.

  • ||

    Don't be ridiculous.

    Global warming is much worse than any of these.

  • Elemenope||

    LMNOP & Ramsey

    Based on the formula for the radius of a black hole, and assuming the accelerator gooses the proton mass up to around 10tev (approx 10 million times the rest mass), the black hole resulting from the collision of two such protons would have a diameter around 10^-46 meters.

    That's less than the Planck distance. The damn thing would evaporate by Hawking radiation within a femtosecond of being born.


    Thanks, Aresen. It's been a while since physics, and I was trying to err on the side of bigger, just in case.

  • Antiglobalist||

    Humans love apocalypse scenarios because suddenly we're off the hook for fixing problems here on earth -- we're doomed anyway, get it? Anyway, let me tell you about my new product...

    I don't think government is gonna solve these problems, especially not the NWO/WorldGov. It's going to require a small group of people to get their act together to set up a human colony on another habitable planet. Halves the chance of extinction.

  • ||

    So, if some cataclysm destroys human life, does that mean the dinosaurs will get a second chance?

    What do you mean, it doesn't work that way?

  • Elemenope||

    Humans love apocalypse scenarios because suddenly we're off the hook for fixing problems here on earth -- we're doomed anyway, get it? Anyway, let me tell you about my new product...

    I don't think government is gonna solve these problems, especially not the NWO/WorldGov. It's going to require a small group of people to get their act together to set up a human colony on another habitable planet. Halves the chance of extinction.


    I love comments like this. *blah blah blah conspiracy crap blah blah* and then right at the end, an excellent point.

    Pearl in the mud, as it were.

  • Al Gore||

    But before becoming too complacent, keep an eye out for reports on the 210-330 meter asteroid Apophis-there's a 1 in 45,000 chance that it could hit the earth on April 13, 2036.

    I can't believe people are wasting money on this when we'll all be burned to cinders from global warming long before then.

  • ||

    ♬Que Sera, Sera,
    Whatever will be, will be
    The future's not ours, to see
    Que Sera, Sera♬

    ;-)

  • Dr. Strangelet||

    The evaporation times for black holes that size is on the order of microseconds.

    Worry more about strangelets.

    http://en.wikipedia.org/wiki/Strangelets#Dangers

    If the strange matter hypothesis is correct and a strangelet comes in contact with a lump of ordinary matter such as Earth, it could convert the ordinary matter to strange matter. This "ice-nine" disaster scenario is as follows: one strangelet hits a nucleus, catalyzing its immediate conversion to strange matter. This liberates energy, producing a larger, more stable strangelet, which in turn hits another nucleus, catalyzing its conversion to strange matter. In the end, all the nuclei of all the atoms of Earth are converted, and Earth is reduced to a hot, large lump of strange matter.

  • ktc2||

    "We'll need an army of virile men scoring around the clock ... I'll do my part. Kiff, clear my schedule."

  • Warmongering Lunatic||

    Neutron stars are bombarded by cosmic rays.

    So neutron stars regularly have LHC-level events happen on their surface.

    So, if LHC-level events create strangelets any reasonable percentage of the time, essentially all neutron stars will have been hit by strangelets.

    Neutron stars are big balls of densely-packed normal-matter neutrons, which means a strangelet created by a collision with a neutron star would inevitably collide with normal-matter neutrons.

    So, if the strange matter hypothesis is correct, and strange matter serves as a catalyst for conversion of normal matter into strange matter, then neutron stars should very quickly be converted entirely into strange matter by contact with a strangelet.

    So if high-energy collisions do create strangelets, and strangelets do convert normal nucleons, neutron stars would have such short lifespans as neutron stars that the number observable from Earth would be approximately zero, while there would be significant numbers of observed quark (that is, strange matter) stars.

    The number of observed neutron stars is much greater than zero; the number of known quark stars is somewhere between three and zero (there are three known candidates).

    Therefore, either high-energy collisions do not create strangelets, or strangelets do not convert normal matter, or both. Which means the LHC will not result in the conversion of the Earth into strange matter.

  • ||

    The first picture in Mr. Bailey's post reminded me of this theory of What Really Killed the Dinosaurs.

    I miss The Far Side.

  • ||


    Based on the formula for the radius of a black hole, and assuming the accelerator gooses the proton mass up to around 10tev (approx 10 million times the rest mass), the black hole resulting from the collision of two such protons would have a diameter around 10^-46 meters.



    I made an arithmetic error here. A 10tev proton has only about 10,000 times its rest mass. The black hole would be only 10^-49 meters in diameter.

    FWIW, a black hole with a 2 x 10tev mass has a size that bears the same ratio to the size of a proton as the thickness of a cell membrane does to the diameter of the observable universe. IOW, it would go right through a normal proton like a bullet through a very hard vacuum and have essentially zero chance of encountering one of the proton's constituent quarks closely enough to absorb the quark during the passage.

  • Metal Messiah||

    I was reading through the links, and had a good laugh at the cosmosmagazine link for WR 104.

    The fifth reader post in starts trashing Hillary Clinton, and then a bunch of other people start going for pages about how God is going to punish the world.

    I wonder if that article got linked on the Drudgereport or Freerepublic?

  • ||

    Morrison started out by noting that we had just past the centenary of the 5-15 megaton Tunguska airburst over Siberia.

    The evidence is that Tunguska may well have been caused by a small asteroid that incinerated in the atmosphere. This makes this type of event far more likely.

    http://www.sandia.gov/news/resources/releases/2007/asteroid.html

  • ||

    It Came From Outer Space

    And this is the message ran...

    http://www.youtube.com/watch?v=iN3azigz608

    Dig it.

  • ||

    ..Shoulda been: "And this is how the message ran..."

    (Oh Preview button, why do I forsake thee?!)

    It's late, I wanna crash. Anyone seen Nena...?

    http://www.youtube.com/watch?v=1SFFLOpylBw&feature=related

  • ||

    Ok-one more New Wave era tune from the beautiful, talented, Nena!

    http://www.youtube.com/watch?v=zw6FtId23Ns&feature=related

  • ||

    I'm was much more comfortable after Aresen wrote "The damn thing would evaporate by Hawking radiation within a femtosecond of being born."

    But I should have stopped reading becore I got to him writing "I made an arithmetic error"

    There's your scientists for you. Next he'll realize he mixed metric and english units in his calculations.

    Run for the hills, the cherokees has escaped Fort Mudd.

  • ||

    And here's a question for you science guys.

    If this thing turns the earth and us into a black hole do we last long enough to enjoy the ride or do we blink out so fast that the E ticket is a waste?

  • ||

    Technion physicist Arnon Dar warned of another space hazard--gamma ray bursts (GRBs).

    Didn't RTFA, of course, but aren't we an incredibly small target? What are the odds?

  • ||

    Oops, clicked too soon.

    Although something like this was the premise for an awesome novel - A. A. Attanasio's Radix, where the beam sterilized/mutated a lot of people and was a carrier wave for the consciousness of alien lifeforms (going on a 10-year+ memory here, accuracy of summary not warrantied).

  • ||

    ...Earth is reduced to a hot, large lump of strange matter.



    I went to a Ren. Fest this weekend. There was all sorts of large, strange matter there. It even might be hot, depending on what you're into.

    So I hardly see what the problem is unless you really dislike fat chicks wearing chain mail.

  • Stormy Dragon||

    Every analysis I see tries to calculate future risk of impact based on the past impact rate. But shouldn't impacts become increasingly rare as time goes on? The number of possible objects remaining to impact with is continually decreasing.

  • LarryA||

    Every analysis I see tries to calculate future risk of impact based on the past impact rate. But shouldn't impacts become increasingly rare as time goes on? The number of possible objects remaining to impact with is continually decreasing.

    Ever play Asteroids?

  • TallDave||

    So if high-energy collisions do create strangelets, and strangelets do convert normal nucleons, neutron stars would have such short lifespans as neutron stars that the number observable from Earth would be approximately zero, while there would be significant numbers of observed quark (that is, strange matter) stars.

    Well, we arguably don't really know enough about neutron stars or strangelets to say what the likelihood is, or whether degenerate matter would be more or less likely to convert than normal matter. Of course, it's exceedingly unlikely.

    Which means the LHC will not result in the conversion of the Earth into strange matter.

    It's certainly very unlikely.

    We may have been hit by strangelets already. Some believe strangelet impacts explain certain seismic phenomena.

    http://www.space.com/scienceastronomy/astronomy/strangelets_020513.html

  • ||


    Stormy Dragon | July 21, 2008, 12:42pm | #

    Every analysis I see tries to calculate future risk of impact based on the past impact rate. But shouldn't impacts become increasingly rare as time goes on? The number of possible objects remaining to impact with is continually decreasing.



    The impact rate was very high in the first 100 million years of Earth's history and tapered off to a low level after the first billion years. By now, we are so far out from the origin that the curve describing the number of events is essentially flat and parallel to the x-axis.

    IOW: Yes the rate is dropping, but the rate of decrease is now lost in the randomness of the events.

  • ||

    Dar pointed out that the gigantic star Eta Carinae at a distance of 7,500 light years has been extremely unstable of late.

    You mean, it was being extremely unstable 7500 years ago...and it's probably already blown, the light just hasn't reached us yet.

  • wizard of oz books||

    With many new announcement about the wizard of oz movies in the news, you might want to consider starting to obtain Wizard of Oz book series either as collectible or investment at RareOzBooks.com.

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