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I took this pic on 16 th November 2016 two days after supermoon using a small telescope and accidentally captured some sort of satellite pic along with the moon.i am curious to know howmany such satellites are currently orbiting moon.enter image description here

PearsonArtPhoto
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preeti
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    Nothing orbiting the moon would be that large by comparison. Assuming that is in fact a satellite, it would have to be a lot closer than the moon. Here is what it looks like when the International Space Station transits the moon. – called2voyage Dec 01 '16 at 16:21
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    Adding to what @called2voyage wrote, anything with a track that straight would have to be a significant distance from the moon or would be in a very, very weird orbit. What was the exposure time for that picture? I wouldn't be surprised if it's an aircraft or something like that... – user Dec 01 '16 at 16:26
  • It was around 8:50 pm in delhi ncr , india when I took this pic. – preeti Dec 01 '16 at 16:32
  • Sorry. "Exposure time" isn't the time at which the picture was taken but rather for what amount of time the picture was being exposed. In other words: was the camera shutter open for 1/100 of a second, half a second, a second, or what? – user Dec 01 '16 at 16:35
  • But I took many other shots continually and only this one captured this satellite kind of image.so I want to be sure of exactly what is this. – preeti Dec 01 '16 at 16:43
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    What kind of camera did you take this with? Also, see http://www.makeuseof.com/tag/exif-photo-data-find-understand/ for how to get the EXIF data, you might just post all of it, it could be helpful. – PearsonArtPhoto Dec 01 '16 at 18:09

3 Answers3

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Unless you had a VERY powerful telescope, you didn't capture an image of a satellite orbiting the moon. From Which artificial satellites in lunar orbit are currently active? we have 3 spacecraft that are known to be orbiting the Moon, and the largest of these is LRO. The solar panels are the largest part, at 10.7 m^2 area. It's too small to even be seen by Hubble, which can only see an object the distance of the moon about 200m in one dimension!

Furthermore, the orbiting period of a satellite would be about 113 minutes, as LRO's period is. The orbital of the object would be about 1/16th of an orbit, so you would have had to have an exposure of about 7 minutes to capture that!

More likely you are either seeing an aircraft, or possibly a satellite orbiting the Earth.

Community
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PearsonArtPhoto
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  • Thanks for such an explanation giving so much of information regarding LRO. – preeti Dec 01 '16 at 18:54
  • The two ARTEMIS probes (formerly known as THEMIS-B and THEMIS-C) have been in lunar orbit since 2010 and are still operating more-or-less nominally, collecting field and particle data. http://artemis.ssl.berkeley.edu/summary.php?year=2016&month=11&day=30&hour=0024&sumType=thb&type=overview – Jim Lewis Dec 02 '16 at 18:49
  • Fair point, I hadn't heard actually they orbited the Moon. The same principal applies. – PearsonArtPhoto Dec 02 '16 at 21:11
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For any camera, the Moon is approximately 0.5 degrees across.

Measuring the photo on my monitor, I find the Moon is 10.5 cm across, while the "satellite" is 3.0 cm from top to bottom. So by simple ratio, the "satellite" is 0.143 degrees across. This converts to a much more useful 0.0025 radians.

So, if the "satellite" was at lunar distance, its length would be:$$Length_{lunar}=0.0025*384000=960 \text{ km}$$If the "satellite" is in geosynchronous earth orbit, its length would be:$$L_{GEO}=0.0025*36000=90 \text{ km}$$If the "satellite" is in low earth orbit, its length would be:$$L_{LEO}=0.0025*400=1 \text{ km}$$If the "satellite" is a plane at around $10,000$ feet, its length (wingspan) would be:$$L_{Plane}=0.0025*3000=7.5 \text{ m}$$

Which of these seem even remotely possible?

DJohnM
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  • Might add too that at a more reasonable airliner cruise altitude of 10 km, the corresponding wingspan would be 25 meters, whereas Wikipedia gives the wingspan of for example the Boeing 767 as a little under 48 meters. Not sure if the 48 meters is length or width tip-to-tip, but especially if it's length, it's definitely in the right ballpark. – user Dec 02 '16 at 13:01
  • I assumed it was a moving streak, with the size not really being all that critical to the size that appeared, but still, interesting thought. – PearsonArtPhoto Dec 02 '16 at 13:33
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This is what a satellite in orbit around the moon actually looks like in an actual photograph. After careful calculations and preparation, LRO was able to photograph LADEE while both of them were orbiting the Moon.

The spacecraft were separated by only 9 kilometers. By comparison, on the evening of your photograph the moon was about 361,000 kilometers from the Earth.

enter image description here

above: Photograph of LADEE taken by LRO, both in orbit around the moon, from here, seemingly cropped, from here.

uhoh
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