# Google Earth: Can a satellite photograph an airplane in flight? **URL:** \ **Category:** Factual Questions\ **Created:** [October 14, 2006, 1:38pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424 "2006-10-14T13:38:41Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [October 14, 2006, 1:38pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/1 "2006-10-14T13:38:41Z")
[Look at this location (Google Earth required).](http://web.acsalaska.net/~fmurtley/airplaneshadow.kmz) Is that the shadow of a small aircraft in flight? It doesn’t really look like a shadow, but it is an image of some sort partially covering the building (an elementary school) that damn sure looks like a an airplane. Any guesses what this could be? Can a satellite photograph an airplane in flight? ---
**Author:** ![Stan\_Doubt](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@Stan\_Doubt](https://boards.straightdope.com/u/Stan_Doubt)\ **Post date:** [October 14, 2006, 1:50pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/2 "2006-10-14T13:50:28Z")
[QUOTE=Fear Itself] [Look at this location (Google Earth required).](http://web.acsalaska.net/~fmurtley/airplaneshadow.kmz) Is that the shadow of a small aircraft in flight? It doesn’t really look like a shadow, but it is an image of some sort partially covering the building (an elementary school) that damn sure looks like a an airplane. Any guesses what this could be? Can a satellite photograph an airplane in flight? [/QUOTE] Yep, there are plenty of planes in the images. There are lots of other interesting things pointed out on the google earth forums. Here’s a link to the transportation forum: [http://bbs.keyhole.com/ubb/postlist.php/Cat/0/Board/EarthTransportation](http://bbs.keyhole.com/ubb/postlist.php/Cat/0/Board/EarthTransportation) ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [October 14, 2006, 2:00pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/3 "2006-10-14T14:00:52Z")
Hmmm… I had a link to a Google sat photo of an aircraft in flight but I guess that grid was updated recently. Anyhow, just google around airports. They are fairly common. ---
**Author:** ![daffyduck](https://avatars.discourse-cdn.com/v4/letter/d/ec9cab/32.png) [@daffyduck](https://boards.straightdope.com/u/daffyduck)\ **Post date:** [October 14, 2006, 2:28pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/4 "2006-10-14T14:28:15Z")
As for the shadow question… the scale of it is too small to be an airplane shadow. Shadows are larger than the object casting them, not smaller. ---
**Author:** ![Bob55](https://avatars.discourse-cdn.com/v4/letter/b/e9c0ed/32.png) [@Bob55](https://boards.straightdope.com/u/Bob55)\ **Post date:** [October 14, 2006, 3:54pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/5 "2006-10-14T15:54:06Z")
Yes, here’s a link where you can download a file to show you every found airplane in flight. [http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/360116/an/0/page/0#360116](http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/360116/an/0/page/0#360116) My favorite is in northern California by a corn field where some farmer had carved “USA BUSH” in huge letters right next to a KC-135R refueling a C5 in flight. (41.51.07, 121.28.43) ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [October 14, 2006, 4:26pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/6 "2006-10-14T16:26:13Z")
[QUOTE=daffyduck] Shadows are larger than the object casting them, not smaller. [/QUOTE] That is not true. The Sun is not a point source; it’s much larger than the Earth and any object on it. As a result, the umbra–the darker inner portion of the shadow–will get smaller, the farther the object is from the shadow plane (in this case, the ground). At the same time, the penumbra–the lighter area surrounding the umbra–gets larger and fuzzier. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [October 14, 2006, 4:33pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/7 "2006-10-14T16:33:23Z")
[QUOTE=Bob55] Yes, here’s a link where you can download a file to show you every found airplane in flight. [/QUOTE] Nice collection! But mine (not in that database) looks different from those, less well defined, sort of transparent. Just a poor photo? Or something else? ---
**Author:** ![JustAnotherGeek](https://avatars.discourse-cdn.com/v4/letter/j/58f4c7/32.png) [@JustAnotherGeek](https://boards.straightdope.com/u/JustAnotherGeek)\ **Post date:** [October 14, 2006, 4:50pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/8 "2006-10-14T16:50:28Z")
[QUOTE=Fear Itself] Nice collection! But mine (not in that database) looks different from those, less well defined, sort of transparent. Just a poor photo? Or something else? [/QUOTE] I wonder if there was a plane that was removed poorly. I think you’re right in saying it’s not a shadow. ---
**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\ **Post date:** [October 14, 2006, 5:38pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/9 "2006-10-14T17:38:47Z")
Note that the images you see at the highest resolutions are not satellite images, but taken from aircraft. This includes the area shown in the OP. ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [October 14, 2006, 5:53pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/10 "2006-10-14T17:53:28Z")
For those without Google Earth, here is is in Google Maps. https://maps.google.com/maps?q=34.081497,%2B-117.749916&ie=UTF8&z=19&ll=34.081422,-117.749864&spn=0.001062,0.002696&t=k&om=1 ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [October 15, 2006, 2:42am UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/11 "2006-10-15T02:42:02Z")
Todays photo in the Astronomy Picture of the Day site ( ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [October 15, 2006, 2:44am UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/12 "2006-10-15T02:44:47Z")
{sorry – hit enter too soon.] Todays photo in the Astronomy Picture of the Day site ([http://antwrp.gsfc.nasa.gov/apod/](http://antwrp.gsfc.nasa.gov/apod/)) shows a series of the International Space Station crossing in front of the moon, as photographed fom the ground in California. You can clearly identify parts of the station in the shadow. ---
**Author:** ![JustAnotherGeek](https://avatars.discourse-cdn.com/v4/letter/j/58f4c7/32.png) [@JustAnotherGeek](https://boards.straightdope.com/u/JustAnotherGeek)\ **Post date:** [October 15, 2006, 1:06pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/13 "2006-10-15T13:06:38Z")
[QUOTE=t-bonham@scc.net] You can clearly identify parts of the station in the shadow. [/QUOTE] [nitpick] Silhouette, not shadow. You’re seeing actual images of the ISS, but they’re too dark compared to the bright moon behind it. There’s no light source that could produce such a sharp shadow of the ISS when it is as far away from the moon as it is. [/nitpick] ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [October 15, 2006, 7:00pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/14 "2006-10-15T19:00:14Z")
In regards to that space station picture, how often does that happen? How long does the space station take to pass the moon? How can I figure out when that will happen next for Eugene, OR. Better be summertime since my “see through clouds” filter is cracked. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [October 16, 2006, 1:00am UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/15 "2006-10-16T01:00:48Z")
The OP’s object is the “ghost” of a small plan visible about 935 feet to the south. It’s entered in the file at the Google Earth forum that **Bob55** linked to, in [this post](http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/641894/page/). [Here’s](http://bbs.keyhole.com/ubb/download.php?Number=642139) a direct link to the real plane. This is an explanation of the ghost phenomenon I found on the Google Earth forum: > [@AZTraveller](#): > > The satellite that takes many of Google Earth Satellite based (high resolution) images is QuickBird it employs linear array CCDs. One set takes panchromatic images (grey scale) and the second set takes multi spectral images (MSI). The MSI imager is mounted in different physical location on the satellite so its images are acquired later in time. > > These images are time re-aligned on the ground on the assumption that there are no moving objects in the field of view. As a consequence any moving object will have a colored image that appears ahead of the moving object and at lower resolutions. These images are double exposures. > > If you look on highways closely where you know vehicles are traveling at 60 plus mph you will observe the same red and blue shadows. I’ve only tinkered a little with Google Earth, but the file with all the [planes in flight](http://bbs.keyhole.com/ubb/download.php?Number=360116) is unbelievably cool. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [October 16, 2006, 6:28am UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/16 "2006-10-16T06:28:05Z")
[QUOTE=commasense] I’ve only tinkered a little with Google Earth, but the file with all the [planes in flight](http://bbs.keyhole.com/ubb/download.php?Number=360116) is unbelievably cool. [/QUOTE] That is cool, although the labels are untrustworthy. East of Toledo, OH is a plane noted “crop duster headed back to base?”. The question mark is appropriate, but the guess is way off. That plane is a DeHavilland DHC-6, Twin Otter (the profile is distinctive, the wings are painted dark behind the twin engines–a common paint scheme for the Twin Otter, and the Google measure tool shows a length and wingspan matching that of the Twin Otter), yet I have never heard of a Twin Otter being used as a crop duster, and if one is, I am fairly sure none are so used in Northwest Ohio. Someone with access to the website simply made a really horrible guess, which calls into question other labels (although each of the sites I looked at DID appear to be flying airplanes). ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [October 16, 2006, 7:09am UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/17 "2006-10-16T07:09:01Z")
[QUOTE=Q.E.D.] That is not true. The Sun is not a point source; it’s much larger than the Earth and any object on it. As a result, the umbra–the darker inner portion of the shadow–will get smaller, the farther the object is from the shadow plane (in this case, the ground). At the same time, the penumbra–the lighter area surrounding the umbra–gets larger and fuzzier. [/QUOTE] For objects on earth the shadow is the same size except for diffraction aroung sharp edges. Yes, there is an umbra and a penumbra but for objects that near the surface I don’t think they are greatly different in size. It’s too late to figure it out and maybe **Q.E.D.** is right about their importance but I think the edge fuzziness it’s mostly diffraction. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [October 16, 2006, 7:23am UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/18 "2006-10-16T07:23:40Z")
Well Hell. It’s not that late so I figured it out and **Q.E.D.** is right. The difference between umbra and penumbra is quite significant. The sun is about 1/2 degree wide and if you take the tangent of that times 8 miles you get a number that makes th penumbra significantly larger than the object. Conversely the umbra is formed by rays that arrive at 1/4 degreed off which makes the umbra significantly smaller. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [October 16, 2006, 1:47pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/19 "2006-10-16T13:47:48Z")
[QUOTE=tomndebb] That is cool, although the labels are untrustworthy. East of Toledo, OH is a plane noted “crop duster headed back to base?”. The question mark is appropriate, but the guess is way off. That plane is a DeHavilland DHC-6, Twin Otter. [snip] Someone with access to the website simply made a really horrible guess, which calls into question other labels (although each of the sites I looked at DID appear to be flying airplanes). [/QUOTE] It’s a user-supported compilation, with almost 2,700 objects so far. I would guess that the cropduster comment is probably from the person who found it. **Cyclonic** , the compiler of the list, seems to be fairly well informed about aircraft, but he may not have checked every single item in detail. Or he may not be as familiar with Twin Otters as he is with commercial airliners or military jets, many of which seem to be correctly identified, AFAICT. (I say all this on the basis of puttering around the forum and Google Earth placemarks file for all or two or three hours last night.) If you go to the thread in the GE forum in **Bob55** ’s first thread above, you can post a message to **Cyclonic** and tell him about the Twin Otter. I’m sure he’ll be grateful and update the file. (You will have to register at GE to post.) ---
**Author:** ![Mayo\_Speaks](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mayo\_Speaks](https://boards.straightdope.com/u/Mayo_Speaks)\ **Post date:** [October 16, 2006, 2:32pm UTC](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424/20 "2006-10-16T14:32:26Z")
[QUOTE=Christopher] In regards to that space station picture, how often does that happen? How long does the space station take to pass the moon? How can I figure out when that will happen next for Eugene, OR. Better be summertime since my “see through clouds” filter is cracked. [/QUOTE] It takes 7.5 seconds for the station to cross the moon, assuming it crosses at the diameter. Reasoning: The moon is .5 degrees across, so it covers (.5)/360 = 1/720 of the distance around the Earth. The station makes one orbit every 90 minutes = 5400 seconds. It will spend 5400/720 = 7.5 of those seconds in front of the moon. Of course, this assumes that the moon and the station line up, which I would imagine is rare (I’m no astronomer/orbital mechanic), and that the station crosses the moon along a diameter (which is not the case in the linked picture). Additionally, for observation one would need a full or almost full moon and a good telescope pointed at exactly the right spot. IMO, that’s too much work for less than ten seconds of viewing. And don’t try to observe [this](http://antwrp.gsfc.nasa.gov/apod/ap060921.html) on your own [Next page](https://boards.straightdope.com/t/google-earth-can-a-satellite-photograph-an-airplane-in-flight/376424.md?page=2)