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Comet May Have Missed Earth By a Few hundred Kilometers
First time accepted submitter afree87 writes "A re-analysis of historical observations at a Mexican observatory suggests Earth narrowly avoided an extinction event just over a hundred years ago. On August 12th and 13th 1883, an astronomer at a small observatory in Zacatecas in Mexico made an extraordinary observation, some 450 objects, each surrounded by a kind of mist, passing across the face of the Sun. This month, Hector Manterola at the National Autonomous University of Mexico suggests these were fragments of a comet. 'If they had collided with Earth we would have had 3275 Tunguska events in two days, probably an extinction event.'"
3275 of em. That's a heck of a shotgun blast.
May have missed ? I'm fairly certain it definitely missed.
And likely just a *little* too early to blame Nikola Tesla... if we would have had any conspiracy theorists left.
Sometimes I think it best not to think about these things...
If you were the President and you knew about this impending doom, would you decide to alert your country?
Go study.
The observer was looking at the sun through a telescope! No wonder he is seeing spots.
How Slashdotters approach all scientific articles:
1. Abounding skepticism.
2. Criticism of scientist's findings and methods used.
3. Explanation of failed logic.
4. Loss of all wonder and awe and appreciation at whatever findings remain.
5 Cynicism and dejection at failure of science.
6. Continued existence of misery and woe and greater skepticism.
My tongue is jammed up against my cheek; otherwise, I'd say more. God bless.
As a scientist, don't author your paper with the font set to Comic Sans.
Sig this!
It would probably have been calamitous but extinction level, maybe not. I mean most of those would probably have landed in the ocean anyway, with maybe a thousand or so dropping on land. The Tunguska event didn't raise too much atmospheric dust or cause much occlusion, and at around 10 megatons might have released in total ten gigatons or so, which is what, twice the total world nuclear arsenal except without fallout.
Apocalypse territory? Certainly. Extinction? Probably not.
cool story bro
Only off by 5 years: http://www.amazon.com/Peshawar-Lancers-S-M-Stirling/dp/0451458737
Huh? You use a sun filter and you can definitely look at the Sun with a telescope.
A successful API design takes a mixture of software design and pedagogy.
While we know that in practice actual asteroid and comet strikes on Earth are very rare, this sort of thing helps illustrate how we need to do a good job tracking the larger threats and preparing to deflect them if necessary. The good news is that the WISE mission http://en.wikipedia.org/wiki/Wide-field_Infrared_Survey_Explorer has successfully tracked most of the large asteroids that have near-Earth orbits and none of them are threats in the immediate future. There are however other dangers. For example, comets that are no longer outgassing could potentially have very elliptical orbits that would not be detected by WISE. Also, there may be smaller asteroids that WISE has not detected that could make a life pretty unpleasant in a more narrow area even if they don't lead to an extinction event. An asteroid that was around a thousand feet across (300 meters) could devastate a city and could easily escape detection from WISE. Moreover, there are some real worst case scenarios. If such an asteroid landed in either Pakistan or India for example they might think that the other had launched a nuclear weapon at them.
In general, we aren't doing enough to deal with potential existential risks. At this point, we don't know if the Great Filter is in front or behind us. http://en.wikipedia.org/wiki/Great_Filter. The basic idea of the Great Filter is that the easiest explanation of the Fermi Paradox is that there's some set of events that make life unlikely to reach the interstellar level. That could be behind us, if for example life arising is unlikely or multicellular life arising is unlikely. But at least some filtration has to be in front of us. It seems that natural events (like asteroid strikes) are not common enough to be the entire filter. But there are other potential filtration events. Learning more about these issues not only helps preserve humanity it also helps get insight into why we seem to be alone. Unfortunately, funding for these sorts of things is tiny. The WISE mission for example was only $320 million and was used not just for the asteroid work but a lot of other good astronomy for objects both inside our solar system and more distant objects. This is a tiny cost compared to what is spent on non-science issues, and is particularly tiny when one considers it as being paid for almost exclusively by a single country.
While it is not impossible that an extinction level event almost happened, I'd like to see a bit more evidence before panicking.
If this comet was so close, so much so that no other observatory on earth was able to see it due to "parallax", how come not one of the 450 or so pieces impacted the earth? (There are no reports of Tunguska sized impacts).
Also, wouldn't it be relatively easy to figure out where this thing was headed and find out where it is now? Unless it was a (very) long period comet or ended up in the sun, we should be able to track it down. In fact, if it exists, shouldn't it be easy to find as it will likely have an orbit that repeatedly intersects earth's orbit? (Ulp!)
Why would you bother panicking in any case?
Sure, if it might happen in the next couple years, might be worth some panic. Last year's near miss? Not even worth a "whew, we dodged that bullet!"....
Note also that it's unlikely that there will EVER be more evidence. This was a sighting from one observatory over 100 years ago. It's moderately unlikely that anyone else noticed it at the time, and even more unlikely that we'll ever find any of these rocks and positively identify them as part of that swarm (after all, if they passed within a few hundred miles of Earth, the entire swarm would've been scattered upon departure).
"I do not agree with what you say, but I will defend to the death your right to say it"
My work here is dung.
And now they're back buying up all 4 million of them this weekend. We're in trouble!
There are two types of people in the world: Those who crave closure
Seems like the fragments would have been close enough to be affected by Earth's gravity possibly pulling them in closer if they made a return trip. I wonder where they are now.
Join the Slashcott! Feb 10 thru Feb 17!
I'm waiting to hear how it's global warming or W's fault - at least pin it on the europeans coming to north america if your lack of appreciation for diversity artificially imposes temporal limits on you understanding of causation...
take the spin out of it & what are you left with? SCIENCE?!?
I'm waiting to hear from the fiscal conservatives who want to cancel the space program and asteroid-hunting programs because the Federal Government shouldn't be spending taxpayer money on such useless endeavors.
Intron: the portion of DNA which expresses nothing useful.
"I was almost hit by a car yesterday"
"Statistically, there's no way you would still be alive if you were hit by a car every single day. What a lair!"
ASCII stupid question, get a stupid ANSI
In fact, if it exists, shouldn't it be easy to find as it will likely have an orbit that repeatedly intersects earth's orbit?
Only if its in the same inclination as the earth relative to the sun. Classic orbital mechanics mistake... just because two things are up there (lets say, ISS and HST) doesn't mean they'll ever come really close to each other.
Gravitational slingshot might mean the orbit has been permanently changed. On a long enough scale, from the perspective of small enough objects, there are no non-chaotic orbits. There are Lagrangian points and there is no reason for long term stability there (even the most stable ones can get swept clean by some orbiting "whatever" that passes near enough or thru the L point).
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Dammit!
Well, back to the drawing board.
Shit!
Hammerfall!!!
Extinction is coming anyway you look at it, more likely would have been a significant reduction in human population moving them back on the tech line (to the cave even?) but then we wouldn't be where we are now.
That would be something to watch from orbit though.
"If any question why we died, Tell them because our fathers lied."
These were simply the spaceships coming to pick the Heavens Gate people. It just came about 150 years too early. That is all.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
The authors propose a link in their paper to fragments of comet 12P/Pons-Brooks.
This is nonsense however, as pointed out here: http://sattrackcam.blogspot.com/2011/10/ot-1883-zacatecas-observation-of.html
The earth has its closest approach to the 12P/Pons-Brooks orbit near December 6th, not August 12th (see diagrams in the link above). Hence, fragments of the latter cannot pass close to earth mid-august (and they do not come even particularly close on 6 December, as the minimal earth to comet orbit distance is still 0.2 AU, i.e. the comet passes closer to the orbit of Venus than to the orbit of Earth).
The whole story has very little substantial fact behind it, and factual errors such as pointed out above do not promote confidence.
Ceterum censeo Carthaginem delendam esse
Then it is just a very astronomically (pun intended) rare statistical anomaly and thus nothing to ever worry about, (unless you are worried about getting struck by Lightning twice in the same year while riding a unicycle and simultaneously getting hit by a bus within your lifetime, in which case you actually have bigger problems) unless they are trying to say that this happens more common then we think, which is to say are you almost hit by a car everyday?
No?
Then yes. They they may not be lairs, but they are misleading you.
Life is too short.
I'm waiting to hear from the fiscal conservatives who want to cancel the space program and asteroid-hunting programs because the Federal Government shouldn't be spending taxpayer money on such useless endeavors.
Usually those wingnuts cue a response from the other wingnuts complaining about how many schools we could build with the military budget.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
The referenced article says the fragments were 50-800 km across. An 800km object 600-8000km from earth would not need a telescope! The original article says 46-795m.
The other issue I have with the story is that if it's disintegrated comet, it had clearly had plenty of time to spread out, as it was "observed" over 2 days. Is it reasonable that it would have spread out to that length (many thousands of kilometers), but still would have remained narrow enough that parallax could be a factor? Wouldn't it at least a thousand kilometer wide? And if so, wouldn't it be visible against the sun over a much wider latitude range?
Strikes me that there are a lot of possible interpretations.
The most obvious of which is the joke just whooshed by you.
Faster! Faster! Faster would be better!
My question would be... how is it that a massive comet could pass near earth and nobody see it at night? Shouldn't it have been visible at night a day later as it traveled away?
Wouldn't this comet leave a persistent train of dust and particles in its old orbit like so many other comets. Why isn't there a the mother-of-all meteor showers every 12th and 13th of August each year?
Good point. Earth's orbital speed is 100,000 km/h. The moon is only 385km away. Things have got to be just-so for that comet to stay in the same parallax for a whole day if it is closer than the moon.
AACK. 385,000km away.
Clearly the Earth is a gun-kata black belt.
"When information is power, privacy is freedom" - Jah-Wren Ryel
Step 1: Read way too much into something someone says, turning it into something absurd.
Step 2: Point out that your misread is patently absurd.
Step 3: Claim they are misleading you, despite the fact that you weren't misled into believing the absurd thing.
Seriously, you're right. Life is too short. Don't waste it going out of your way manufacturing things to complain about.
"Convictions are more dangerous enemies of truth than lies."
Sounds like Weapons of Mass Destruction. Wasn't Dick Cheney or Donald Rumsfeld around in 1883?
Gently reply
I guess the short version *is* I think what they are saying is "absurd".
They say "may", but it is a pretty weak "may", in that it is most likely garbage.
If you care to believe their postulation that all life on earth almost ended just over 100 years, ago that's your business.
I am simply saying from a science and statistical standpoint I believe it is very doubtful, and if that is the case, it is likely getting news because it is sensational, which is likely why is was published in the first place.
You talk about misreading, but you seem to not understand what I posted. I didn't see a complaint. It was an opinion. Mine. That the story was BS from a science perspective. Your post on the other hand, does appear to be a complaint, about my post, so take your own advice. At least I had a point to make, whereas you seem to lack even that.
I am trying to work some kind of bull fighting joke out of this. Something to do with a Red cape, a comet flying by and some Mexican yelling OLE! I have to get back to class and don't have time for these shenanigans.
Take the Red Pill.
The objects were observed during two days, which were between 600 and 8000 km removed from earth, between the sun and the earth, as they were seen passing in front of the sun. The escape velocity in that range is 10.7 to 7.4 km/s. As we didn't have an impact and haven't developed a ring or an extra satellite they must have had at least this speed relative to earth. The article doesn't mention at what exact times the observations were made, but according to this calculator there were 13 hours of daylight on those dates at that location, so to have those observations made on two days the objects kept passing within this distance interval during at least 14.5 hours (11 hours night time plus the 3.5 hours observation time mentioned in the article). At 7.4 km/s the objects were spread out over at least 390,000 km and traveled that distance relative to the earth, and yet they all managed to pass within a distance of 600-8000 km from the earth surface, and in front of the sun seen from one observatory and not from others.
How likely is that?
For some bizarre reason the parent post was modded down, so I'm quoting it, as it's one of the most clearly thought out posts in this entire thread.
They are already cutting the defense budget by half and the social security / medicare budget is already twice that of the defense budget. I'm all for some sort of safety net and taking care of old folks but holy shit thats a lot of money.
That brings me to an interesting point, / . is just "the ramblings of socially-inept, technology-literate news-mongers".
Just think of how many killer robots and smart bombs we could build if we just cut the SS / Medicare budget in half and re-appropriated it to the Defense budget. It would double the defense budget!
That brings me to an interesting point, / . is just "the ramblings of socially-inept, technology-literate news-mongers".
I'm waiting to hear from the fiscal conservatives who want to cancel the space program and asteroid-hunting programs because the Federal Government shouldn't be spending taxpayer money on such useless endeavors.
Most self-proclaimed "conservatives" in Congress usually insist that they want a socialized space program with a central government authority which has exclusive rights for access to space... private companies are neither needed nor wanted except in a support role where cost-plus contracts are handed out to the lobbyist who has schmoozed them with the best campaign contributions. Of course all of this is good because it helps out the local congressional district with billions of dollars of "stimulus money" to help keep local bureaucrats employed.
The "liberal Democrat" answer: privatized spaceflight from companies competing for fixed-price contracts open to competition and demonstrating that they are able to actually accomplish the task before they are awarded any money.
It was former senators William Proxmire and Walter Mondale who were most in favor of cancelling the "space program" in earlier eras. Guess which political party they belonged to, if you don't already know?
No, I don't get space politics either, just don't let your head get warped out on this issue.
I'll be blunt: I'm not buying it. I give details on my blog, but I think there are too many holes in the idea. For one thing, comets aren't that small; passing within a few thousand klicks of one would put us inside the debris field. We'd have seen vast numbers of meteors. For another, no one else saw it? At all? Comets can be visible during broad daylight - I've seen one myself - yet there's not a single other observation of a comet that close from any other person on Earth. So I am very, very, very skeptical.
*** Phil Plait, aka The Bad Astronomer http://www.badastronomy.com
How do we know those weren't spaceships?
--
make install -not war
"No, I don't get space politics either"
It's actually very simple now. The primary competency of military-industrial complex is extracting government funding by managing the procurement and political process. This is why you have say NorthroBoeingheed winning all sorts of contracts to perform random technology and other services from the government.
In particular over the last 30 years, the MIC has split their facilities geographically for maximum political coverage, these days usually in the deep-'red' (and obviously not Red) districts of powerful Republican Congressmen, since they are the pro-military-spending ones. Space hardware is just an minor extension of this blob. The United Launch Alliance has a monopoly on launching NRO and DOD payloads and they charge lots and lots of money.
SpaceX and say Orbital Sciences have a prime competency in cost-effective rocket engineering and not government, and their facilities are concentrated in Los Angeles and Northern Virginia, and they have much less money. Northern Virginia is 'purple' and LA is 'blue'.
So that's why most Republicans are opposed to private-sector cost-effective NASA contracts, because in a fair technical and economic competition, SpaceX will massacre their political supporters in NorthroBoeingheed.
For those interested, here is a drawing of a swarm of cranes, observed on the solar disk with "slow motion": http://gallica.bnf.fr/ark:/12148/bpt6k209642v/f72 (this is from the same journal, L'Astronomie, which is on line on the Gallica web site) It is reported that people suspected the earth atmosphere to be responsable for many sights of objects seen across the solar disk. In this paper, the author believed at first he was observing metors. From the size of the birds (assumed to be 1 meter), he calculated they were flying at a height of 9 km.
The actual amount of the budget spent on the military seems to be more than shows up on most pie charts. The most obvious example is the $53 billion or so spent on Veterans affairs. There's no way that shouldn't be considered part of the military budget, but it shows up instead as more than 10% of discretionary spending.
If the comet or fragments were that close to earth, earths gravity would have had an effect of having it hit the globe. But perhaps the comet was traveling too fast, so that earths effect on it's trajectory was insignificant.
Leslie Satenstein Montreal Quebec Canada
The original paper, published in 1885 in L'Astronomie can be read online here: http://gallica.bnf.fr/ark:/12148/bpt6k2096403
Build military schools. After all, teaching people how to kill other people is much more economically useful than teaching people how the world works, how to think critically etc.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Citation please?
As a geologist who has been sent to work in Siberia, and who intends to get paid to go there again, I take a non-trivial interest in the Tunguska event (despite not having got closer to the site than a couple of thousand km. Yet.). I've not heard of any evidence for the nature of the presumed impactor. Evidently you have. Citation please.
One point to remember (quoting from the 1963 Meteorica report) : "Under field conditions it is precisely the magnetic spheres that most readily lend themselves to concentration and identification."
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
I like it. All the efficiency of government and all the accountability of the military!
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
I'm waiting to hear from the fiscal conservatives who want to cancel the space program and asteroid-hunting programs because the Federal Government shouldn't be spending taxpayer money on such useless endeavors.
Usually those wingnuts cue a response from the other wingnuts complaining about how many schools we could build with the military budget.
No. Those "other wingnuts" complain about how many schools we could build for a tiny fraction of the military budget, say the cost of occupying Iraq for a week, or procuring a single B2 bomber...don't even go there, dude.
Because, with spending per pupil among the highest in the world, insufficient spending is what is wrong with our schools. If only we wouldn't spend so much on the big, bad military, we'd have world-class schools!
Of course, you wouldn't come right out and say that - it's just as wing-nutty as saying that the government has no place running social programs. It totally ignores the facts. Instead you imply that cutting the military might somehow divert money toward the schools. Which implies that the schools need more money to make them better.
It would be beautiful in it's elegance if it wasn't so downright intentionally misleading.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
They are already cutting the defense budget by half and the social security / medicare budget is already twice that of the defense budget. I'm all for some sort of safety net and taking care of old folks but holy shit thats a lot of money.
Really? Take your lips away from the Fox News kool-aid. Presently, the US defense budget is $671B for fiscal 2012, which is 20% higher than the highest year of the Bush II era. With the exception of 1998, US defense spending has increased every year that it has been reported, with Obama significantly out spending Bush II, even if you factor in the supplemental spending for the Iraq and Afghan wars (listed as OCO, ongoing combat operations, in the cited sources). The only time the US defense budget actually changed downwards from the previous year was in 1998, when it dropped by a whopping 6/10 of one percent.
Wouldn't Fox news want to point this out about Obama? Presumably if I was a Faux news watcher and dipping into their kool-aid I would think this would be something I would have mentioned. The SS budget is 701 billion, the Medicare budget is 793 billion. That totals almost 1500 billion dollars, that is over twice the defense budget. 43 percent of the Federal budget is spent on SS/Medicare, 20 percent on defense. At any rate, the defense budget being cut is inevitable as part of the spending cuts. The Senior voting block will never let their SS benefits go away.
That brings me to an interesting point, / . is just "the ramblings of socially-inept, technology-literate news-mongers".