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Tagged: Space junk
- This topic has 49 replies, 8 voices, and was last updated 4 months, 1 week ago by Howard Lawrence.
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27 November 2023 at 2:22 pm #620346Dr Paul LeylandParticipant
Shouldn’t it possible to extract useful information from the sky background in the photometrically calibrated images and spectra we take ? If so there could already be a huge (untapped ?) historical source of data covering a range of passbands, locations, air mass and atmospheric conditions
Cheers
RobinThat is a damned good idea! I alone have over 30,000 images neatly catalogued, most of which contain little but stellar images so determining the background sky brightness should be possible.
The FITS headers of mine not only have RA, Dec and time recorded, they also have altitude and azimuth (admittedly easily computed from the first three) so more than just air mass is available – the distribution over the sky, such as city lights, can also be determined. About the only thing I don’t have recorded is the weather condition at the time of exposure but perhaps there are other public records of that too.
2 December 2023 at 7:14 am #620413Howard LawrenceParticipantThis is a very interesting question Robin and one that needs investigation. I suspect that there will be scientific reports on this subject somewhere,
2 December 2023 at 7:15 am #620414Howard LawrenceParticipanthttps://www.bbc.com/travel/article/20231123-the-last-places-on-earth-to-see-truly-dark-starry-nights
These amazing images by Jordi Busqué illustrate what dark sky campaigners are working for. Very few people will experience these conditions today.
With the rise of satellite constellations, will it be possible in future to make similar images, for instance those made near dusk and dawn?2 December 2023 at 7:16 am #620415Howard LawrenceParticipantHere is what looks like a useful publication from the EU office of the Director General for the Environment: https://op.europa.eu/en/publication-detail/-/publication/5727bc7c-843c-11ee-99ba-01aa75ed71a1/language-en/format-PDF/source-296551457
I have only skimmed it so far.9 December 2023 at 2:54 pm #620560Howard LawrenceParticipantComing to your local sky soon maybe? Apparently this event was the result of a malfunction in a “green” house blackout blind system. But shouldn’t the rules be no blinds then don’t switch on the lights? These vertical farms are likely to be increasingly common in future. The story comes via contributors on the Dark Sky International forum.
https://www.kwtx.com/2023/12/04/researchers-weigh-pink-glow-sky-coming-lettuce-farm-temple/9 December 2023 at 4:16 pm #620561Robin LeadbeaterParticipantComing to your local sky soon maybe?
Also seen here
https://www.bbc.co.uk/news/uk-england-humber-67095602There it seems to imply the decision to draw the blinds is temperature dependent not to reduce light pollution and is likely to occur again under certain circumstances
27 January 2024 at 9:46 am #621450Howard LawrenceParticipantThe International Union for Conservation of Nature has published World at Night, Preserving natural darkness for heritage conservation and night sky appreciation.
This looks like an excellent general guide to global light pollution issues. It is 160 pages so I’ve not read it yet, but the page (7) on amateur astronomy and stargazing is particularly good. I especially like the opening sentence.
Thanks to John Barentine, one of the authors, for announcing this.https://portals.iucn.org/library/sites/library/files/documents/PAG-033-En.pdf
27 January 2024 at 10:30 am #621451Howard LawrenceParticipantReflectors in space could make solar farms on Earth work for longer every day. Is this a sensible idea?
https://www.space.com/reflectors-in-space-increase-solar-farm-capacity
27 January 2024 at 11:19 am #621453Dr Paul LeylandParticipantNot obviously cost effective. It’s much cheaper to double the collecting area on the ground than to do so in space.
27 January 2024 at 5:16 pm #621462Robin LeadbeaterParticipantThere could be some financial advantage to extending the time over which power can be generated rather than increasing capacity on the ground. For a region heavily dependent on solar power, the price of night time electricity must presumably attract a high premium due to the high cost of storage or alternative generating capacity.
27 January 2024 at 6:45 pm #621464Dr Paul LeylandParticipantRobin: true.
I question whether it is cheaper to put large structures in space or whether to put large structures (such as transmission lines) on the ground at a range of longitudes.
Or, for that matter, to install storage mechanisms to convert daylight solar energy into nighttime electricity. Batteries, in the general sense of the word, are relatively cheap. Raising a cubic kilometer of mass a hundred metres stores a lot of energy and uses technology which has been well understood and implemented for a hundred years. Melting and re-solidifying a phase-change material, such as NaCl, likewise.
4 February 2024 at 12:37 pm #621564Howard LawrenceParticipantA new paper sheds fresh light on a subject that CfDS have used in past campaigns – the disruption caused by artificial light to the lives of insects. The new science has been featured on various news outlets. A straightforward article about it can be found on the Conversation website.. https://theconversation.com/the-surprising-reason-why-insects-circle-lights-at-night-they-lose-track-of-the-sky-221387 There is a link to the original paper from this article and a video compilation showing insects in flight.
4 February 2024 at 11:00 pm #621586Robin LeadbeaterParticipantI have just been listening to one of the scientists involved in that study on BBC world service Science in Action
https://www.bbc.co.uk/sounds/play/w3ct4sdl
starting at 22:40Robin
5 February 2024 at 9:36 am #621588Howard LawrenceParticipantThanks Robin. I will listen to it later.
5 February 2024 at 9:39 am #621589Howard LawrenceParticipantThis is an interesting article about the prospect of an artificial plasma shield being generated by the high masses of future de orbiting satellites. It is little studied at present but the potential impact on planet Earth could be enormous. So, another reason to campaign against satellite constellations until this and other issues are resolved.
https://spaceweather.com/archive.php?view=1&day=03&month=02&year=2024
5 February 2024 at 11:24 am #621590Robin LeadbeaterParticipantInteresting. I don’t think the comparison between the mass deorbited and the amount of material in the Van Allen belt is particularly helpful as the two are not comparable (We already receive ~ 40T/day of metals from meteorites) but at the future projected rate of 23 satellite deorbits a day (in the paper) the amount of additional material would appear to be comparable.
7 February 2024 at 11:13 am #621604Mr Giovanni Di GiovanniParticipantI have carefully viewed the articles posted by Mr Christopher. They are very interesting, well laid out and equally well developed topics. I am interested in their content, and for this I thank the author for making them available in this forum. For a few years now, I have been interested in sky transparency and observing sunrise and sunset light in order to detect the ‘optical depth’ parameter. I have a small archive of data from about 300 observations. I will try to identify the possible existence of a correlation between the theory Christopher applies and the one I use for my observations. I hope this will provide good guidance for further experiments and studies. Thank you Christopher.
17 February 2024 at 4:19 pm #621789Howard LawrenceParticipantThe UN is now talking about the issue of satellite constellations (at last). Will it result in anything positive in time? We must hope so. https://www.iau.org/news/pressreleases/detail/iau2401/
17 February 2024 at 10:05 pm #621791Mr Giovanni Di GiovanniParticipantI always hoped for their title.
https://www.youtube.com/watch?v=P8Xk2e3ApiA&ab_channel=JORGEC
What a beautiful sky, all black. Back then, the sky was filled with clusters of stars, which you could touch with your hands, even from the cities. Remember?
Unfortunately today our starless sky is all white. I see white, it’s over!
5 March 2024 at 2:55 pm #622031Howard LawrenceParticipantThis article is a comprehensive critique of the satellite swarm issues, conveniently in one place. https://bigthink.com/starts-with-a-bang/outer-space-human-pollution/
So the notion that satellites are just the latest lies are true!😀 -
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