Slashdot Log In
How to Discover Impact Craters with Google Earth
Posted by
CowboyNeal
on Sat Mar 11, 2006 09:33 AM
from the for-fun-and-more-fun dept.
from the for-fun-and-more-fun dept.
Maikel_NAI writes "Believe it or not, Emilio Gonzalez, a Spaniard amateur began his crater search at home after reading an article about the discovery of Kebira, the biggest one found in the Sahara. After a couple of minutes he located two craters. After checking the records, he realized these were completely new, and now two geologists confirm his findings. And there is more, these craters may be part of a chain studied by NASA geologist Adriana Ocampo, so if it's confirmed that these new ones are part of the same episode, it could mean the definitive evidence for her theory of an asteroid broken into pieces fallen in that area."
This discussion has been archived.
No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
Full
Abbreviated
Hidden
Loading... please wait.
Google Earth (Score:5, Interesting)
Re:Google Earth (Score:4, Informative)
Parent
Re:Google Earth (Score:5, Funny)
Parent
So would the lawyer for these people... (Score:5, Interesting)
From the TV specials that I've seen about this, it looks like area 51 was an R&D facility for rockets, planes, and other weapons. Unfortunatley, that requires a lot of toxic chemicals. Also, the workers would burn a lot of the failed projects so that they wouldn't be discovered. Like many areas of the US, one of the biggest polluters is the US Government.
Parent
Re:Google Earth (Score:5, Informative)
Speaking of other manmade items found on google, last september a man found ruins of a roman villa near his house via Google Earth. [nature.com] It is proving itself to be a very fun and useful tool indeed.
Parent
Re:Google Earth (Score:2)
In this case, the skill requirements to participate are essentially zero, so every extra eyeball can potentially give us great results.
woo hoo!
(Just don't point out the nuclear silos. They hate when you do that.)
Re:Google Earth (Score:4, Insightful)
Zoom in on the coastline of southern Cuba and you'll see a narrow bay cutting deeply into the shore. With a little imagination you can almost see the IVth, Vth and VIth ammendments of the Constitution of the United States of America being violated.
I don't know if these sorts of out-of-date images of military installations have any practical value, but they do give a certain valuable sense of reality regarding the existence of places that many people would like us to ignore, or forget. It's hard to think of the prison camp where innocent people are being incarcerated without trial[*] as being "out of sight, out of mind" when you can fire up Google Earth and see it plain as day.
[*] Do the math: there are 500+ people there, mostly captured in battlefield conditions in villages and farms. We know the cops, in the best of circumstances, sometimes get the wrong guy. We know the courts, in even better circumstances, sometimes convict the wrong person. So we no with what would be ordinarily called certainty that a non-trivial number of innocent people are being held, indefinitely, without trial, without legal recourse. Even with the most generous assumptions the number comes out to 25 or so. The only question is: are the goals being pursued so valuable and the means being used to pursue them so valuable as to justify the certain incarceration of innocents? "Is life so dear, and peace so sweet..?"
Parent
Re:Google Earth (Score:4, Interesting)
Well, dunno if you'd consider any of this [hbo.com] as an anomaly, but it's an equally topical use of Google's map technology (season premier is tomorrow, kids).
Maybe someone can find Jimmy Hoffa?
Parent
How about Roman Ruins? (Score:2)
Get yourself Google Earth [google.com] and look around. I'm sure a couple of google searches will tell you where most of the nuclear tests have taken place.
This map [atomicarchive.com] will even show you where they've taken place.
I wouldn't even be surprised if many of these things are already cataloged someplace for Google Earth.
Cheers
CoralCached (Score:5, Informative)
This one will get nailed hard (Score:3, Informative)
Re:CoralCached (Score:3, Informative)
Historical views (Score:5, Interesting)
Re:Historical views (Score:2, Interesting)
Re:Historical views (Score:4, Informative)
Besides, the military has earth-watching satellites for their own private use to watch for such things. They need not rely on a civilian tool for it.
Parent
Re:Historical views (Score:2, Informative)
Re:Historical views (Score:5, Informative)
What you're talking about is called change detection. It's most commonly used for biodiversity inventory and urbanization growth measurements. The successfullness of change detection is dependent on a lot of variables, but can work very well. I used a sort of change detection to help delineate the transient snow altitude- a common elevation at which glaciers change from predominately ice-covered to predominately snow-covered.
There are lots of different systems that take these images. Some can reshoot an area in a days, some once a month, a year, maybe never again. Again, there a lots and lots of factors involved. Do a search for remote sensing basics and you'll probably find lots of cool stuff about it. If you're into this kind of thing...
Parent
Crater studies and Air Force DSP (Score:3, Interesting)
The US has had much of the world's surface under continuous large scale infrared observation for 25 years or more with the Air Force DSP [af.mil] program. It can easily detect the smallest asteroid or comet impacts. I don't know if a scientific survey of its data has ever been done.
Re:Historical views (Score:2)
Technically, craters are the result of an imapact, not the impactor itself. But more importantly, we already know about about substantial meteorite impacts because of their signature on the global seismological / nuclear explosion sensing network.
The visible craters are probably far too old (Score:5, Interesting)
If you mean to search for impact craters, then it's probably not at all practical for the types of craters that are discussed in this article. The initial crater mentioned is 195 kms in diameter. The article's not specific about the other two, but it seems that they're also on the order of many kilometres in diameter. Add to that that they'll be very very old, probably on the order of many tens of thousands to millions or hundreds of millions of years depending on the size and state. The erosion of them is part of the main reason they wouldn't have been discovered until now.
If any of these craters were created in modern times, we'd very definitely know about it, irrespective of where on the Earth it was. If the entire Earth's sky didn't turn red and light wasn't blocked for years and large populations weren't killed, the impact would show up quite obviously on geological equipment for detecting Earth tremors.
There are probably smaller impact craters forming on a more common basis if there were extremely high resolutions available, but they'd also be eroding much more quickly. Consequently you'd likely need very high resolutions, and need new ones frequently, and then some reliable algorithm for filtering out every farmer (or rabbit) who's dug a small hole for some reason.
I'm an amateur astronomer but I'm not an expert on meteorite impacts, so I'd be interested to hear the comments of someone who knew a bit more about satellite images and impact craters. It seems pretty unlikely to me from my own understanding that it'd be infeasible, though.
Parent
"Optical Recgnition"? (Score:4, Interesting)
Re:"Optical Recgnition"? (Score:5, Informative)
Hi, I'm Emilio, the "discoverer"
The main problem is that circularity is not a proof by itself, because it can be caused by other natural processes.
Impacts don't have to be circles necessarily, it depends on the path inclination. They could be ellipses too. (I'm learning a lot these days)
Another problem is that I found with Google Earth great portions of Africa are cloud covered. If would be great if they could make the mosaics showing only pictures without clouds.
I don't think, but maybe I'm wrong, that there are many structures missing with such clear structure. I was really lucky, but most structures should be very erosioned like the candidates close to Arorunga, that need radar images to show details.
I'm now also using NASA World Wind, and it has some interesting features shuch false colors that help to better distinguishing structures. Anyway Google Earth is great for sweeping big areas
Parent
Re:"Optical Recgnition"? (Score:5, Interesting)
Parent
Re:"Optical Recgnition"? (Score:5, Informative)
worldwind://goto/world=Earth&lat=21.28825&lon=19.
For his two features in worldwind.
Parent
Re:"Optical Recgnition"? (Score:2, Insightful)
Google Earth's eye for aerial detail is great, but Worldwind is definitely not to be overlooked.
Re:"Optical Recgnition"? (Score:3, Interesting)
Re:"Optical Recgnition"? (Score:3, Interesting)
Just remember that craters have many causes. What is more both of the "craters" in Africa are not impact craters as they are not "blasted out" like is supposed to happen on impact. If they are in fact craters, they are probably plasma discharge craters or volcanic structures. www.thunderbolts.info has a lot of data on this. See picture of the day for 3/10/2006 etc. See the Sedan crater
Re:"Optical Recgnition"? (Score:2)
Google Earth tourism (Score:5, Interesting)
You can find many interesting sights on Google Earth (and Maps). Some of the ones I've found interesting are:
Australia's Great Barrier Reef
The USS Arizona memorial at Pearl Harbor
China's Three Gorges dam
The Golden Gate Bridge
Re:Google Earth tourism (Score:2, Interesting)
Re:Google Earth tourism (Score:5, Interesting)
Parent
Re:Google Earth tourism (Score:5, Informative)
Parent
How cool is that? (Score:5, Interesting)
Re:How cool is that? (Score:3, Insightful)
The idea that amateurs don't (or can't) do good science or make important discoveries is a more recent addition to popular culture - and it's wrong.
Admittedly, there are fields where it's true - like particle physics, stem cell research, or transplant biology, since the "entry level" for equipment and training is something you're not going to be able to pick up on the cheap (unless you're Bill G).
That said, there are many fields where 'amateurs' not only make important discoveries, they're actually
Free information means news information (Score:4, Insightful)
I love this! You free up information, allow the unwashed masses access to it, and people find hidden treasure. Think how much we'd never know if all this was DRMed, locked and restricted!
Google, don't ever change.
It's a neat idea, but... (Score:5, Informative)
Here's some examples:
a circular structure in Louisiana [google.com] -- this is related to a salt structure beneath the surface. There are several in the area. It has been somewhat enhanced by artificial canals and other development.
volcanic cones [google.com] in various stages of erosion in Mexico. Volcanic cones are usually fairly easy to distinguish from impacts, but if they are deeply eroded (e.g., after the eruptions have stopped, and the peak has been worn down to the igneous plug in the center), they could be confused with well-eroded craters.
salt domes and folding-related structures [google.com] in the Zagros Mountains of southern Iran.
There is *alot* of awesome geology visible from space, especially in desert areas without much vegetation (I *love* Google Earth), but people should evaluate the possibilities skeptically. In the sum total of circular structures out there, probably only a fraction of a percent have anything to do with impacts.
For comparison, here are a few legitimate impact structures:
Clearwater Lakes [google.com] in northern Quebec, Canada.
Lake Manicouagan [google.com], also in Quebec. The best places to look for craters is often these very old parts of the continents (called continental shields), where the surface has been exposed for a long, long time, even on geological scales.
In the same area you'll also notice round structures like these [google.com] that relate to igneous intrusions (usually granites or other plutonic rocks) and which have nothing to do with impacts.
Meteor Crater, Arizona [google.com] is a "simple" crater, which is bowl-shaped. Most of the bigger ones (like the ones above) are "complex craters" with one or more raised rings or central areas.
I guess if Google Earth ever adds a geological map layer, it might make hunting for impacts a little less hit-and-miss, but geological maps aren't usually how people navigate or locate a business, so I can't see that happening soon
Googlicious! (Score:5, Funny)
*yawn* You mean this? (Score:5, Informative)
But here is a post about the imagery [alteviltech.com] that is currently "ready" there will also be a full color imagery dataset by release time.
There is also an add-on to view Venus [nasa.gov] imagery in World Wind. Though that is not yet with a 3D texture yet.
Don't get me wrong.. GE is a nice image viewer, but you can't really expand it's boundries that far.
Parent
Google Sight Seeing (Score:5, Interesting)
Dr. Strangelove (Score:2, Funny)
Re:Dr. Strangelove (Score:2)
Mustard gas doesn't leave a crater.
Re:Dr. Strangelove (Score:2)
OMG! Right here! (Score:2, Funny)
There's one near Boston (Score:2)
http://maps.google.com/?ll=43.114142,-71.191235&s
I hear Google Earth is nice... (Score:2, Redundant)
Surely it can be done.
Worked for me! (Score:2)
Alternative (Score:2)
I found some! (Score:4, Interesting)
2046'24.47"S
1618'18.43"E
You can see the multiple rings and the raise central structure. Also, just north of it is a smaller structure which may be associated with the first impact (sometimes you get crater chains):
2043'56.35"S
1617'28.12"E
Finally, there's a very strange (to a layman) structure to the SW that would have to be a very oblique impact crater if it is one, but I've never seen a crater like that; it looks more like a natural circular feature:
2049'8.00"S
16 7'48.59"E
If any geologist can look into this, let me know. I'd bet money the first one is an impact structure, though!
Bruce
What about this one? (Score:4, Interesting)
Is this in a database somewhere? It's like a bulls-eye of small islands. I found this while looking around with Google Earth. It's near Lake of the Woods Minnesota USA / Canada.
http://maps.google.com/?ll=49.169583,-94.491348&sp n=0.249613,0.464859&t=k [google.com]
There is a really obvious circular pattern in the center of that one, and a slightly less obvious one just off to the east.
Re:What about this one? (Score:3, Informative)
But it is hard to believe that no one has noticed, given there's a (small) town sitting on top of one of them!