This morning (December 2, 2019) at about 6 UTC+1 and at a geographic place of about 52° N 13° E I saw a chain of 12 or more satellites in two groups (5 or more + 7), flying with equal distances in each group from west to east over the zenith (i.e. far from the equator). Does someone know this constellation of satellites or a web site which may be searched for orbits of satellites visible by naked eye?
Hi, you are perhaps talking about the A-train observation satellites but I think that they are less than 12:
https://en.wikipedia.org/wiki/A-train_(satellite_constellation)
See also the Space X stralink project.
Thank you, Richard, for your reply. However, there were definitely more than 5 satellites. A colleague told me right now that these were some of the Starlink satellites launched by SpaceX (https://en.wikipedia.org/wiki/Starlink_(satellite_constellation)). I checked with https://www.heavens-above.com/, and the data for this morning given there coincide with my observation. These satellites were launched in the course of last month, therefore I have never seen them before. At this moment, there are 122 Starlink satellites. "In total, nearly 12,000 satellites will be deployed by the mid-2020s, with a possible later extension to 42,000." This will be a mess for many ground-based astronomical observations and a danger for other satellites due to future space debris.
Hi, you are completely true this large amount of satellites will create in the future potential debris and will be a danger for other satellites.
hi, I'm guessing starlink - these are visible to the naked eye and are now still close together. see https://www.heavens-above.com/ or https://www.n2yo.com/?s=28485 to find satellites above your position
In June this year the IAU expressed concerns about such satellite constellations (https://www.iau.org/news/announcements/detail/ann19035/). An overview of the discussion including the reply by Elon Musk is given in the short paper "Starlink: a new threat to observational astronomy?" in Journal of the British Astronomical Association 129(4), p. 200 (2019), https://www.britastro.org/journal_item/18859 (available online only for BAA members).
"On Monday, January 6 at 9:19 p.m. EST, or 2:19 UTC on January 7, SpaceX launched its third launch of Starlink satellites from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station, Florida." (https://www.spacex.com/webcast) This means that as of today, SpaceX has deployed 182 Starlink satellites.
IAU has published a new page with texts and images on the impact of Satellite Constellations including Starlink on astronomy (https://www.iau.org/public/themes/satellite-constellations/) and a new press release expressing its concerns (https://www.iau.org/news/pressreleases/detail/iau2001/).
From the Holiday Greetings by IAU President Debra Elmegreen, Dec. 23, 2021:
"The IAU is in final negotiations to establish the new Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference . Meanwhile, at the Dark and Quiet Skies for Science and Society II Conference , several hundred participants discussed implementation of recommendations to mitigate threats to our view of the night sky."
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