How to Discover Impact Craters with Google Earth

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."

Google Earth

[gcnaddict]

Ok, so we can easily find anomalies caused by nature, but how about anomalies caused by us? I mean things like Area 51 and nuclear bomb test sites... I wouldn't mind seeing a few of those.

So would the lawyer for these people...

[AnonymousPrick]

Area 51 workers suing Gov. [abovetopsecret.com]

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.

Historical views

[mgkimsal2]

I know we don't have the previous satellite images from years gone by, but would it be practical to use some sort of image diffing program to look for changes in satellite imagery in the future? Yes, you'd get all the new building activity and whatnot, but we should also be able to tell when new craters hit (or other bigger changes happen) automatically. 'course, I've no idea how often global satellite images are updated, or how long it takes, so it might not be practical any time soon... Hundred years or so from now, it would be fun (if nothing else) to watch movies of how areas changed, both from direct human changes (buildings, etc) and from natural forces (coastal erosion and so on).

"Optical Recgnition"?

[bigattichouse]

Anyone have photo recgnition software that might look for the "raised circle" in a ring foot print and then wander over the map looking for interesting locations. You could use that database as a great testbed.

Google Earth tourism

[FuzzyBad-Mofo]

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

[VisceralLogic]

I found the pyramids at Giza. That's pretty cool.

Re:Historical views

[mordors9]

You certainly would think that the government would be running an algorithm on the satellite photos that would detect any serious change in what it was seeing. If not to see if California had fallen into the Ocean yet, then to see troops massing along a border somewhere...

How cool is that?

[blueZ3]

It's easy to get caught up in the idea that either everything cool that's discoverable by amateurs has already been discovered, or that it takes years of experience or expensive tools to do "new" work in science. This discovery, by someone whose interest was piqued a few days ago by a translated article, should serve as a reminder that there are still things out there that people without a formal science degree can discover.

Re:Google Earth tourism

[Ford Prefect]

The Register [theregister.co.uk] had a fun black helicopters competition [theregister.co.uk] - looking for covert military stuff with Google Earth. They've had plenty of weird Google Earth things featured [google.co.uk], including an incredible, um, giant profanity [theregister.co.uk]. Wahey.

Re:Google Earth

[value_added]

Ok, so we can easily find anomalies caused by nature, but how about anomalies caused by us?

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?

Re:"Optical Recgnition"?

[cluckshot]

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"?

[Sporkinum]

Good job Emilio! I decided to try Worldwind as well, and your discoveries stick out like a sore thumb using Nasa's program. Yes, Google Earth scrolls faster, but I think Worldwind is better for seeing the detail.

Google Sight Seeing

[ntsucks]

If you just want to look at cool stuff with Google Maps/Earth, without the searching. This place www.googlesightseeing.com [googlesightseeing.com] has tons of cool stuff found in Google Maps/Earth.

Crater studies and Air Force DSP

[amightywind]

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:It's a neat idea, but...

[Anonymous Coward]

N22 06 53 E 17 55 15 (new?)
N21 44 E 19 20
N21 17 E 19 20
N22 38 E 19 18

N22 02 E 19 13 (part of chain...?)
N22 09 E 19 27

N19 05 E 19 14 (possibly new?)

The visible craters are probably far too old

[jesterzog]

I know we don't have the previous satellite images from years gone by, but would it be practical to use some sort of image diffing program to look for changes in satellite imagery in the future? Yes, you'd get all the new building activity and whatnot, but we should also be able to tell when new craters hit (or other bigger changes happen) automatically.

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.

Re:It's a neat idea, but...

[Anonymous Coward]

By "geological map layer", I mean color-coded formations and other structures. Topography and marking features such as volcanoes is a start, but geologists usually map whole areas by the type of bedrock or surface sediments, the relative age, major faults, volcanoes, et cetera. Most countries have a geological survey of some kind whose job it is to map the geology of the country. In the U.S., it is the United States Geological Survey, in Canada, it is the Geological Survey of Canada, and there are often state or provincial efforts too. There is substantial economic interest via mining, agriculture, and water resources, so geology is important enough to document properly. We do live on the Earth, after all.

Most of the world has been mapped, though at highly variable levels of detail. For example, here's an interactive geological map of Kentucky [uky.edu]. See all the pretty colors? Each is a rock formation of a particular age.

Fusing the detailed local compilations into one global map would be very challenging because of differences in terminology and conventions, but there are several generalized continent and global-scale compilations that have been published on paper.

None of this detracts from the fact that the current incarnation of Google Earth is *very* cool.

I found some!

[SirBruce]

There's two very interesting structures in Namibia, and I'm almost certain one of them is a crater:

  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?

[slagheap]

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:"Optical Recgnition"?

[Forbman]

Hmm... I remember watching a movie of a study done by NASA to see why impact craters always seem to be circular. They shot high-speed pellets at sintered silica sand blocks, and filmed the results. Didn't matter what they did w.r.t. velocity or angle of impact (short of the absurd, like 5 degrees elevation), they all came out circular. How many ellipsoid craters are found on the moon, for example?