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ANOTHER source of "astronomical" pollution.
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#2
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ANOTHER source of "astronomical" pollution.
RichA wrote:
A--hole New Zealander. https://mashable.com/2018/01/25/rock...for-astronomy/ Couldn't be worse than Iridium flsshes. This is one satellite, Iridium are 88. It might ruin some astrophotos, but so does Iridium and aircraft. Heavens-above.com has already added it to their satellite list. I won't even be able to see it until March. I can see Iridium flashes every (clear) night. -- I recommend Macs to my friends, and Windows machines to those whom I don't mind billing by the hour |
#4
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ANOTHER source of "astronomical" pollution.
On Sunday, 28 January 2018 03:49:08 UTC-5, Anders Eklöf wrote:
RichA wrote: A--hole New Zealander. https://mashable.com/2018/01/25/rock...for-astronomy/ Couldn't be worse than Iridium flsshes. This is one satellite, Iridium are 88. How many reflective sides does an iridium have? Reportedly, the reflections will only be mag 7 (if that is true) which will have no impact on observing but will be visible in photos. |
#5
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ANOTHER source of "astronomical" pollution.
Chris L Peterson wrote:
On Sun, 28 Jan 2018 09:49:01 +0100, (Anders Eklöf) wrote: RichA wrote: A--hole New Zealander. https://mashable.com/2018/01/25/rock...for-astronomy/ Couldn't be worse than Iridium flsshes. This is one satellite, Iridium are 88. It might ruin some astrophotos, but so does Iridium and aircraft. It is likely to be worse than either, because it is so bright, and because it is bright across its entire path, not just in a flare zone. Do you have ANYTHING to back up that claim? Like having seen it. Or calculations? Get a clue. it's about 1,5 meters in diameter, being smaller than an Iridium satellite. It also has many more reflective sides than Iridium, making it impossible to be even nearly as bright - even in the flare zones. From what I have read I expect it to be hard to spot. Mag 4 at best. -- I recommend Macs to my friends, and Windows machines to those whom I don't mind billing by the hour |
#6
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ANOTHER source of "astronomical" pollution.
On Sun, 28 Jan 2018 23:48:59 +0100, (Anders
Eklöf) wrote: Chris L Peterson wrote: On Sun, 28 Jan 2018 09:49:01 +0100, (Anders Eklöf) wrote: RichA wrote: A--hole New Zealander. https://mashable.com/2018/01/25/rock...for-astronomy/ Couldn't be worse than Iridium flsshes. This is one satellite, Iridium are 88. It might ruin some astrophotos, but so does Iridium and aircraft. It is likely to be worse than either, because it is so bright, and because it is bright across its entire path, not just in a flare zone. Do you have ANYTHING to back up that claim? Like having seen it. Or calculations? Get a clue. it's about 1,5 meters in diameter, being smaller than an Iridium satellite. It also has many more reflective sides than Iridium, making it impossible to be even nearly as bright - even in the flare zones. From what I have read I expect it to be hard to spot. Mag 4 at best. I do not expect it to be as bright, as I commented on some other post here recently. For the reason you state, which is that its planar reflective surfaces are much smaller than the Iridium antenna panels. Mag 4 seems much too dim an estimate. The maximum brightness of an Iridium flare is around mag -8. This disco ball satellite appears to have panels about 1/30 the area of an Iridium antenna. But probably more reflective. So we are talking about a difference of 3-4 magnitudes. That would put its flares at -4 or brighter- extremely obvious to the human eye and more than enough to trash most of the science in any telescopic image. And unlike an Iridium flare, this is a tumbling body, which means a much wider area is catching specular reflections, and that over the entire path of the satellite across the sky. |
#7
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ANOTHER source of "astronomical" pollution.
On Monday, 29 January 2018 02:16:02 UTC+1, Chris L Peterson wrote:
I do not expect it to be as bright, as I commented on some other post here recently. For the reason you state, which is that its planar reflective surfaces are much smaller than the Iridium antenna panels. Mag 4 seems much too dim an estimate. The maximum brightness of an Iridium flare is around mag -8. This disco ball satellite appears to have panels about 1/30 the area of an Iridium antenna. But probably more reflective. So we are talking about a difference of 3-4 magnitudes. That would put its flares at -4 or brighter- extremely obvious to the human eye and more than enough to trash most of the science in any telescopic image. And unlike an Iridium flare, this is a tumbling body, which means a much wider area is catching specular reflections, and that over the entire path of the satellite across the sky. And, if it should prove "successfully" visible, how long before we can expect a vast, tumbling "copyrighted" sugar bomb and CO2 bottle in orbit? Commercial heavy lifters aren't going to notice a lightweight advertising symbol cadging a ride for less than a manager's annual bonus. Origami would seem an appropriate "form" for all sorts of advertising crap being sent up there. These will dwarf this poor man's, tiny experimental disco ball. Damn! I hadn't thought of light pollution. That would make orbital advertising much more difficult in their mega-city markets. Never mind, they will just have to scale up their flashing gizmos to make them easily visible to anyone who glances up from their 'phone. What about colossal flashing burgers in geostationary orbit? Easily affordable for global '**** shovellers.' |
#8
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ANOTHER source of "astronomical" pollution.
On Sun, 28 Jan 2018 09:03:13 -0700, Chris L Peterson
wrote: It is likely to be worse than either, because it is so bright, and because it is bright across its entire path, not just in a flare zone. No, it's not bright across its entire path. It has 72 reflective triangular surfaces. Only half of then can be effective of course since the other half will be in shadow. And less than half of those will shine towards the Earth, the others will shine into space. So it will generate some 15 flare zones, each giving flares considerably fainter than Iridium. One satellite which really was bright along its entire path was Echo II which was in orbit from 1964 to 1969. It was a spherical balloon 41 meters in diameter covered with mylar. It did shine at mag -6 or -7 when brightest, and it did shine continuously during the pass if it was outside the Earth's shadow. I've never seen any other satellite shine that brightly, except the peaks of the brightest Iridium flares, and they are brief. |
#9
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ANOTHER source of "astronomical" pollution.
On Mon, 29 Jan 2018 21:16:07 +0100, Paul Schlyter
wrote: On Sun, 28 Jan 2018 09:03:13 -0700, Chris L Peterson wrote: It is likely to be worse than either, because it is so bright, and because it is bright across its entire path, not just in a flare zone. No, it's not bright across its entire path. It has 72 reflective triangular surfaces. Only half of then can be effective of course since the other half will be in shadow. And less than half of those will shine towards the Earth, the others will shine into space. So it will generate some 15 flare zones, each giving flares considerably fainter than Iridium. That assumes the satellite is not changing orientation. The description I've read says it is deliberately placed in a tumbling orbit so everyone sees a sparkling path. |
#10
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ANOTHER source of "astronomical" pollution.
On Mon, 29 Jan 2018 16:34:50 -0700, Chris L Peterson
wrote: On Mon, 29 Jan 2018 21:16:07 +0100, Paul Schlyter wrote: On Sun, 28 Jan 2018 09:03:13 -0700, Chris L Peterson wrote: It is likely to be worse than either, because it is so bright, and because it is bright across its entire path, not just in a flare zone. No, it's not bright across its entire path. It has 72 reflective triangular surfaces. Only half of then can be effective of course since the other half will be in shadow. And less than half of those will shine towards the Earth, the others will shine into space. So it will generate some 15 flare zones, each giving flares considerably fainter than Iridium. That assumes the satellite is not changing orientation. The description I've read says it is deliberately placed in a tumbling orbit so everyone sees a sparkling path. No it doesn't assume that. Flare zones can have irregular shapes, and they will as the ball tumbles. |
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