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Strange Satellite Trail?


Jonesdee
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I wouldn't expect an object at constant altitude to show such variation in direction over such a small area. But as something like a balloon or lantern could easily display this behavior as it rises through different air layers. I've observed it myself. 

My guess would be a rising balloon illuminated by light pollution. A lantern tends to flicker, which I would expect to show in the trail being much more variable in brightness. 

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12 minutes ago, neil phillips said:

Will leave you with this different size and shape of lanterns. Viewed from a multitude of possible distances and angles from the lens

different size chinese lanterns - Bing images

Fact that you have different size lanterns - does not mean we can't still do the same.

There is something called linear programming or operational research in general

https://en.wikipedia.org/wiki/Linear_programming

You create a volume of what is possible. Lookup smallest Chinese lantern that will actually fly. Similarly - do the same for largest. That puts bounds on distances. We can compare that with possible speeds - again very slow or very fast - and also on brightness of the flame - from very faint to very bright.

Some things are linearly dependent, some are quadratic in nature - like brightness versus distance.

But in any case - you will still be right - no way to prove what it really was. According to wiki:

"A proof is sufficient evidence or a sufficient argument for the truth of a proposition"

and I guess you can always decide that presented proof is not sufficient enough.

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8 minutes ago, Paul M said:

I wouldn't expect an object at constant altitude to show such variation in direction over such a small area. But as something like a balloon or lantern could easily display this behavior as it rises through different air layers. I've observed it myself. 

My guess would be a rising balloon illuminated by light pollution. A lantern tends to flicker, which I would expect to show in the trail being much more variable in brightness. 

We have no idea how large trajectory we are talking about here. We must set some bounds.

I highly doubt that it is balloon based on "unresolved object" constraint.

Balloon will be at least 10-15cm in diameter in order to be able to fly - and we already shown that object of that size needs to be at least 10 kilometers away in order to be unresolved in the image (and that is with assumption of 2"/px resolution when in fact it is closer to 1.6"/px - so it must be even further away). I don't think that balloon will reflect enough of light in order to produce such trail.

Eyeballing length of trail - it is about 3° long.

Trail that object traveled if it is larger than 10cm is at least 500 meters (constant distance to telescope - path in plane perpendicular to optical axis - shortest possible path). It did so in 3 minutes or less so lower bound for speed is ~2.8m/s

Another interesting point that we did not discuss - is being in focus. How far away it needs to be in order to be in focus like it is in image?

Btw, I just checked - model rockets don't get very high - up to 2000 feet or there about. Sure, there has been records with rockets being put in space - like 116Km altitude but that has been done with special rockets and teams and what not.

 

 

 

 

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23 minutes ago, vlaiv said:

Fact that you have different size lanterns - does not mean we can't still do the same.

There is something called linear programming or operational research in general

https://en.wikipedia.org/wiki/Linear_programming

You create a volume of what is possible. Lookup smallest Chinese lantern that will actually fly. Similarly - do the same for largest. That puts bounds on distances. We can compare that with possible speeds - again very slow or very fast - and also on brightness of the flame - from very faint to very bright.

Some things are linearly dependent, some are quadratic in nature - like brightness versus distance.

But in any case - you will still be right - no way to prove what it really was. According to wiki:

"A proof is sufficient evidence or a sufficient argument for the truth of a proposition"

and I guess you can always decide that presented proof is not sufficient enough.

As i said originally to many variables to be certain. Yes you can learn different estimates as you correctly point out.  But being definitive requires more than that here unfortunately.  Anyway i do not think it is a lantern. The light source appears too uniform. Sometimes i think we have to accept we may never know. Based on the limitations of the data. We can guess of course. But thats likely all it will really ever be.  If others get fun searching great. Its just a fun discussion. Anyway hope i didnt come across as too dismissive. I just struggled to see the end point i suppose. Good luck everyone have a good discussion. 

Edited by neil phillips
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7 minutes ago, ScouseSpaceCadet said:

I worked it out. The pixie grapevine tells me this time of year Santa puts the sleigh through its MoT. I'm guessing during a test run one of the reindeer farted and left a contrail.

Interesting, that's exactly what my Rice Crispies told me!

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That "in focus" thing got me thinking. How to best go about it.

We have 85mm scope that operates at 455mm. That is about F/5.35.

In order for defocus blur to be 1px wide at best - focus position for this object needs to be at most 5.35px away from infinity focus. Pixel size is 3.76µm so we have defocus of max ~20µm or 0.02mm

We have known formula that 1/f = 1/f1+ 1/f2 - where F1 and F2 are distances of object and image from the lens.

1/455mm = 1/455.02 + 1/X

X = 103512955mm = 103512.955m = 103.512955Km

This is even more interesting - so minimum distance according to trail being in focus is 100Km.

 

 

 

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7 minutes ago, vlaiv said:

We have no idea how large trajectory we are talking about here. We must set some bounds.

I highly doubt that it is balloon based on "unresolved object" constraint.

Balloon will be at least 10-15cm in diameter in order to be able to fly - and we already shown that object of that size needs to be at least 10 kilometers away in order to be unresolved in the image (and that is with assumption of 2"/px resolution when in fact it is closer to 1.6"/px - so it must be even further away). I don't think that balloon will reflect enough of light in order to produce such trail.

Eyeballing length of trail - it is about 3° long.

Trail that object traveled if it is larger than 10cm is at least 500 meters (constant distance to telescope - path in plane perpendicular to optical axis - shortest possible path). It did so in 3 minutes or less so lower bound for speed is ~2.8m/s

Another interesting point that we did not discuss - is being in focus. How far away it needs to be in order to be in focus like it is in image?

Btw, I just checked - model rockets don't get very high - up to 2000 feet or there about. Sure, there has been records with rockets being put in space - like 116Km altitude but that has been done with special rockets and teams and what not.

 

 

 

 

Your getting me going now. Yes it appears to be at infinity doesnt it. Minimum distance Can be calculated. Which obviously will tell you quite a bit of information. But not definitive enough to identify the object with much certainty. You will do better in finding what its likely not. Than what it likely is.  Good luck im off have fun guys

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