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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.
You don't look at the sun directly through a telescope so I assume then that we're talking about a large number of shadows crossing a projection.
Strikes me that there are a lot of possible interpretations.
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.
The objects could have been an alien invasion force- but they passed us by when they realised we hadn't even invented the iPhone yet.
"That's the way to do it" - Punch
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
Just shows how they're all retarded!
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!)
A) Um ya. I am sure some observation were all that accurate over 100 years ago. Not to mention the re-interpretation of that data.
B) Statistically if earth was commonly hit by 3275 Tunguska hits every 100 years, believe me, we would know about it.
C) The Aztecs MAY HAVE had contact with Aliens, and been involved in a deadly hunt involving space faring Predators, however I doubt it.
Classic BS fear science (if you can even regard it as science) for sensationalism and attention.
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?!?
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.
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.
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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
1. First Post!
2. Abounding skepticism.
3. Asshole making predictions regarding what kind of comments will be posted
4. Goatse/GNAA troll
5. Criticism of scientist's findings and methods used.
6. Explanation of failed logic.
7. Loss of all wonder and awe and appreciation at whatever findings remain.
8. Cynicism and dejection at failure of science.
8. Continued existence of misery and woe and greater skepticism.
We have to send Bruce Willis back ASAP!
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?
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
I think they may be exaggerating things a bit. From the sounds of it this comet was a rubble pile. Tunguska was a slab of metal and rock. Depending on its origins there could have been a few Tunguska type rocks in there, but I highly doubt even a majority of them were as such. While I have little doubt that it would have been a devastating event with many thousands to maybe a few million dead which would have immensely effected our history, I highly doubt it would have been anywhere near an ELE (Extinction Level Event).
Sounds like Weapons of Mass Destruction. Wasn't Dick Cheney or Donald Rumsfeld around in 1883?
Gently reply
Since it happened in 1883, I wasn't planning on panicking in any case. The chance of the Earth being hit by these comet fragments in 1883 is zero.
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?
no worries....mankind has been an ongoing extinction event for ages now.
The article claims the fragments are from the comet 12P/Pons-Brooks.
This can be easily falsified:
http://sattrackcam.blogspot.com/2011/10/ot-1883-zacatecas-observation-of.htmlhttp://sattrackcam.blogspot.com/2011/10/ot-1883-zacatecas-observation-of.html
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.
8. Yelled at Ma... whilst yelling at kids to get off my lawn.
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
That was just 2 weeks before Krakatoa exploded.
http://en.wikipedia.org/wiki/Krakatoa
How do we know those weren't spaceships?
--
make install -not war
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.
Or hit the moon? to change it orbit?
The sun will burn out one day.
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