Did my phone camera see Mars?

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Space Ninja
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Did my phone camera see Mars?

Post by Space Ninja » Mon Jun 25, 2012 6:27 am

Hi! I was messing around with my phone this afternoon and I decided to take a picture of the Moon. Here's what I got.

As you can see, there's something in the bottom left corner. The camera's flash was disabled, so I don't think it was a piece of dust or something flying by. I checked Google Sky Map, and
here's what it showed me at the time I took the picture (June 24th, 4:16 PM Pacific Time).

So my best guess is that my phone camera somehow got a picture of Mars. I'm fairly skeptical, though. For one, I wasn't able to get it again in subsequent shots. Also, based on a rough calculation using an equation for resolution that I picked up in my physics class last semester, the camera's aperture should be somewhere in the neighborhood of twenty times too small to see Mars. So if it's not Mars, what is it? And if it is, how did my lousy phone camera manage to see it once?

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Re: Did my phone camera see Mars?

Post by Markus Schwarz » Mon Jun 25, 2012 9:23 am

Hello,

I did a quick "back of the envelope" calculation for the angular dimension (theta) of Moon and Mars. I used theta=arctan(2R/d), where R is the radius and d is the distance to earth. Using R_Mars=3400 km, d_Mars=205 x10^6km, I got theta=0.002 degrees, whereas the Moon has 0.5 degrees (R_Moon=1700km, d_Moon=384 000 km). Unless I got the numbers completely wrong, Mars' angular diameter is about 250 times smaller than that of the Moon. But the angular extend of your UFO ("unidentified fotographed object") is about half that of the Moon. Given that, and that you could not reproduce it, I don't think your camera saw Mars.

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Re: Did my phone camera see Mars?

Post by Space Ninja » Mon Jun 25, 2012 3:07 pm

Hmm...maybe I was being a bit too optimistic :P Thanks, though!

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Chris Peterson
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Re: Did my phone camera see Mars?

Post by Chris Peterson » Mon Jun 25, 2012 3:40 pm

Markus Schwarz wrote:I did a quick "back of the envelope" calculation for the angular dimension (theta) of Moon and Mars. I used theta=arctan(2R/d), where R is the radius and d is the distance to earth. Using R_Mars=3400 km, d_Mars=205 x10^6km, I got theta=0.002 degrees, whereas the Moon has 0.5 degrees (R_Moon=1700km, d_Moon=384 000 km). Unless I got the numbers completely wrong, Mars' angular diameter is about 250 times smaller than that of the Moon. But the angular extend of your UFO ("unidentified fotographed object") is about half that of the Moon. Given that, and that you could not reproduce it, I don't think your camera saw Mars.
This question can't really be addressed by considering optical resolution. Even point sources show significant angular sizes in images... especially images made with poor optics.

The way to approach this is by considering the image scale. I note that the unidentified spot is approximately 16 lunar diameters from the Moon, or around 8°. At the time of the image, Mars was 20° from the Moon (40 lunar diameters). So there's no way the spot can be Mars.
Chris

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neufer
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Re: Did my phone camera see Mars?

Post by neufer » Mon Jun 25, 2012 4:34 pm

Chris Peterson wrote:
This question can't really be addressed by considering optical resolution. Even point sources show significant angular sizes in images... especially images made with poor optics.

The way to approach this is by considering the image scale. I note that the unidentified spot is approximately 16 lunar diameters from the Moon, or around 8°. At the time of the image, Mars was 20° from the Moon (40 lunar diameters). So there's no way the spot can be Mars.
The fact that they are of approximately equivalent apparent magnitude would also exclude this from being Mars.
Art Neuendorffer

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Chris Peterson
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Re: Did my phone camera see Mars?

Post by Chris Peterson » Mon Jun 25, 2012 4:45 pm

neufer wrote:The fact that they are of approximately equivalent apparent magnitude would also exclude this from being Mars.
Agreed, although some cameras apply unexpected transfer functions to an image (basically, odd gamma values), especially in an image like this which can fool the "image category" calculator- the software that tries to figure out if it's a landscape, snow scene, etc. The result can be a really skewed brightness profile. So I'd say this is evidence against it being Mars, but not completely exclusive evidence (such as the object being in the wrong place).
Chris

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BMAONE23
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Re: Did my phone camera see Mars?

Post by BMAONE23 » Mon Jun 25, 2012 5:13 pm

I would suggest urge you to play a little more and take another image of the moon and see if the anomoly is still visible in a new image

Space Ninja
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Re: Did my phone camera see Mars?

Post by Space Ninja » Mon Jun 25, 2012 6:27 pm

BMAONE23 wrote:I would suggest urge you to play a little more and take another image of the moon and see if the anomoly is still visible in a new image
I took a few more pictures, but it wasn't visible. So maybe it was just a camera artifact or perhaps even a stray bug.

Thanks for your input, everyone! :)

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Re: Did my phone camera see Mars?

Post by bystander » Tue Jun 26, 2012 1:16 am

Moon Sweeps Past Mars In Monday's Night Sky
Discovery News | via Joe Rao of Space.com | 2012 June 25
As darkness deepens on Monday evening (June 25), look about one-third of the sky up from the southwest horizon. There you'll see a fat crescent moon, and a moderately bright yellow-orange "star" hovering well above and to its left.

But that's no star ... It's Mars
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
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