# Circular objects on Google Earth (2002)

J

#### johne1618

##### Guest
Five circular objects, each apparently 80 meters in diameter, on Google Earth Pro. Satellite photos of Florida, USA taken on Dec 31, 2002.

Could these be droplets on the lens or are they real objects? A water droplet of 20 microns diameter at 10 cm subtends the same angle as an object 80 m in diameter at 450 km.

Correction: The image is from aerial photography not satellite. According to Google, the aerial photography is taken from around 400 m. Therefore a water droplet of 2 cm diameter at 10 cm subtends the same angle as an object of 80 m in diameter at 400 m. That's a large water droplet!

1/ 26°44'58.16"N 80° 4'29.30"W

2/ 26°45'0.86"N 80°11'21.66"W

3/ 26°54'11.14"N 80° 4'36.54"W

4/ 26°54'11.79"N 80°14'43.58"W

5/ 27° 0'12.85"N 80°14'37.95"W

Reddit:

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Higher-resolution "satellite" images on Google Earth/Maps are actually composites of aerial photos taken from planes. The OP images are in the same small area and probably have been taken during the same flight. I guess this may be a single spec of dirt on the camera front lenses that popped up in several places on the composite photo.

Higher-resolution "satellite" images on Google Earth/Maps are actually composites of aerial photos taken from planes. The OP images are in the same small area and probably have been taken during the same flight. I guess this may be a single spec of dirt on the camera front lenses that popped up in several places on the composite photo.

Agreed. The fact that it's not in focus at all says that it's some kind of aberration interrupting the light and preventing it from focussing. The orientation of the banding does seem to be somewhat aligned with the direction of the shadows (though not perfectly), which would support the idea of it being sunlight reflected by some optical imperfection.

Correction: The image is from aerial photography not satellite. According to Google, the aerial photography is taken from around 400 m. Therefore a water droplet of 2 cm diameter at 10 cm subtends the same angle as an object of 80 m in diameter at 400 m. That's a large water droplet!
Since the object appears to be mostly spherical, if it's a droplet it must be much smaller than two centimeters for surface tension to maintain that shape. Perhaps the error is in your assumption of "10 cm" as the distance. Have you any information on the camera used?

Correction: The image is from aerial photography not satellite. According to Google, the aerial photography is taken from around 400 m. Therefore a water droplet of 2 cm diameter at 10 cm subtends the same angle as an object of 80 m in diameter at 400 m. That's a large water droplet!
Judging by the resolution of these particular aerial photos, I'd say they were taken from an altitude of several kilometres, putting the "droplet's" size estimate into the millimetre range. A higher altitude provides a wider area coverage that probably were more important at the time of filming. The resolution of more recent images is generally higher than these.

It could easily be a drop of water or debris stuck to the glass lens cover. Here’s one example:

https://www.vexcel-imaging.com/ultramount/

Vexcel is purported to be one of the sources for Google imagery.

We also see that the dot is generally in the same position in each image, given that images are rotated and cropped so they stitch together properly and align to north. Seems to indicate that the dot is not moving relative to the camera.

Since the object appears to be mostly spherical, if it's a droplet it must be much smaller than two centimeters for surface tension to maintain that shape. Perhaps the error is in your assumption of "10 cm" as the distance. Have you any information on the camera used?
I'll grant you "circular," I'm not sure about "spherical."

But I don't think it is water -- I'd expect water to "lens" the light coming through it and flip the image.

If my understanding of the optics of that is off, somebody feel free to correct me.
Instead, it seems that the light is passing straight through, just blurred. (Upon further looking, that MAY be an artifact of coincidence, with many of the pictures just happening to have a light something on the ground passing behind a the lighter portion of the "ufo," so I'm soliciting opinions on that I guess)

Anyway, I wonder if it's a smudge left by a drop of dirty water after the water evaporated?

We also see that the dot is generally in the same position in each image, given that images are rotated and cropped so they stitch together properly and align to north. Seems to indicate that the dot is not moving relative to the camera.
Agreed. I followed the 'horizontal' line through the two points at 26°54'N from the East to the West and found two more spots on the grid:

But I don't think it is water -- I'd expect water to "lens" the light coming through it and flip the image.
View attachment 49487
If my understanding of the optics of that is off, somebody feel free to correct me.

Notice the background in that one is horrifically out of focus, whilst its virtual image through the water lens is in perfect focus. Were you to put the normal background back in focus again, the water drop and its virtual image would then take the role of being horrifically out of focus.

I vote water droplet on the window in front of the aerial camera. The droplet has the same general shape/colours on all the images, because the selection is made from a local area on Google maps, and thus can be from the same series (from the flight).

Notice the background in that one is horrifically out of focus, whilst its virtual image through the water lens is in perfect focus. Were you to put the normal background back in focus again, the water drop and its virtual image would then take the role of being horrifically out of focus.

I've never done a waterdrop photo before, so this is kinda crummy, but shows the point decently enough:
http://fatphil.org/tmp/drop_in.jpg
http://fatphil.org/tmp/drop_out.jpg
public domain - those can be moved onto MB via whatever magic you guys use.

Can you do the same ones, but then with a small(er) aperture setting?

Yes ...

But I just packed everything away

I'll flip to my pancake lens, and take f/1.8, f/6.3, and f/22 for both focus distances, which should demonstrate the effect even more, about the same (was f/5.6), and much less.

Yes ...

But I just packed everything away

I'll flip to my pancake lens, and take f/1.8, f/6.3, and f/22 for both focus distances, which should demonstrate the effect even more, about the same (was f/5.6), and much less.

Yuck - horrible iris on that lens:
http://fatphil.org/tmp/far_f2.jpg
http://fatphil.org/tmp/far_f6.jpg
http://fatphil.org/tmp/far_f22.jpg
http://fatphil.org/tmp/near_f2.jpg
http://fatphil.org/tmp/near_f6.jpg
http://fatphil.org/tmp/near_f22.jpg
And as you can see from the thermostat on the wall, it's now time to disappear into the sauna

Thanks for the effort, however, I am not sure if it gives some clues..
The type of cam/lens used and the distances involved do matter, and of course a flat glass plane with a waterdrop stuck to it would be an idea.
I will try it myself, if I can find time... (I am renovating my floor as we speak).

Since the object appears to be mostly spherical, if it's a droplet it must be much smaller than two centimeters for surface tension to maintain that shape. Perhaps the error is in your assumption of "10 cm" as the distance. Have you any information on the camera used?
Sorry I don’t - it was just a (probably bad) guess.
Judging by the resolution of these particular aerial photos, I'd say they were taken from an altitude of several kilometres, putting the "droplet's" size estimate into the millimetre range. A higher altitude provides a wider area coverage that probably were more important at the time of filming. The resolution of more recent images is generally higher than these.
Several kilometers height sounds more likely than just hundreds of meters.

Several kilometers height sounds more likely than just hundreds of meters.
Here is one of my photos taken 10 years ago during a flight from London to LA. It pictures a bit of Lavic Lake in Mojave Desert, CA. Small white spots are out of focus small ice crystals inside the plane window. Their projections on the ground 10+ km below is about 200 m in diameter.

Notice the background in that one is horrifically out of focus, whilst its virtual image through the water lens is in perfect focus. Were you to put the normal background back in focus again, the water drop and its virtual image would then take the role of being horrifically out of focus.
Yes, but would it still be flipped?

Yes, but would it still be flipped?

Yes. Were I to take a sequence of photos that were identical apart from the distance to the focal plane, in between the drop and the background, the inverted image in the near focus one would gradually just blur away progressivesly as the focal plane moves back.

Anyone have a marble? That's way bigger than a drop of water, and way easier to get to behave. A crystal ball would be perfect!

I have a flat-on-one-side colored-glass bead at home, I'll mess with it tomorrow. Being flat in one side would be a good analogue for a drop on glass...

OK, I've been messing about with drops of stuff on a window or on the lens of my camera. Tested water, elmers glue as an analogue for water with stuff suspended in it (dirty water), diluted glue for water without as much stuff in it, and salt residue after a drop of water evaporates. Resulting pics are below. I was unable to duplicate the images in the Johne1618's opening post closely. This may well be a function of the capabilities of my camera, distance to the window not matching the setup taking the aerial shots used in Google Earth, dismal cloudy day not matching light conditions in the originals, etc. Anyway, here are the images I got.

A -- Blob of water on window, camera about a meter back. Not circular, but it looks so unlike the original images that it does not much matter about the shape. Lensing effect is strong.

B -- Smudge of white glue on window, again about a meter from the camera. Maybe the best match I got, and not particularly close.

C -- Drop of water on the lens. This surprised me, the lensing is totally lost in the blur. The blurry border, compared to other images below, was also a surprise.

D-- Dried salt residue on lens. Along with B, maybe the closest to the "UFO." Note the sharper edge than the previous picture. Residue from saltier water, so thicker salt, and a sunny day, may get pretty close. But I'm losing my light as the weather here worsens so can't test that today.

E --Around 50% diluted white glue on lens. Not significantly different from water OR undiluted glue, surprisingly.

I think the answer is going to be dried salt deposit or dirty translucent water of the correct thickness and distance from the lens (which would assume shooting the original images from behind a protective window to get a little distance off the lens.) Next time the weather cooperates with a bit more sun I'll see if I can do better.

J
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