Concerns about ground based astronomical observations: a step to safeguard the astronomical sky [IMA]

http://arxiv.org/abs/2001.10952


This article aims to highlight the impact for ground based astronomical observations in different windows of the electromagnetic spectrum coming from the deployment of fleets of telecommunications satellites. A particular attention is given to the problem of crowding of circumterrestrial space by medium/small size orbiting objects. Depending on their altitude and surface reflectivity, their contribution to the sky brightness is not negligible for professional ground based observations. With the huge amount of about 50,000 new artificial satellites for telecommunications planned to be launched in Medium and Low Earth Orbit, the mean density of artificial objects will be of >1 satellite for square sky degree; this will inevitably harm professional astronomical images. Only one of these project, Starlink@SpaceX’s, was authorized by US Federal Communication Commission, F.C.C. and plans to deploy about 42,000 not geostationary satellites, which will shine from the 3rd to the 7th magnitude in sky after sunset and before sun dawn. All satellites will leave several dangerous trails in astronomic images and will be particularly negative for scientific large area images used to search for Near Earth Objects, predicting and, eventually, avoiding possible impact events. Serious concerns are common also to other wavelengths eligible for ground based investigation, in particular for radio-astronomy, whose detectors are already saturated by the ubiquitous irradiation of satellites communication from Space stations as well as from the ground.Understanding the risk for astronomical community, a set of actions are proposed in this paper to mitigate and contain the most dangerous effects arising from such changes in the population of small satellites. A dedicate strategy for urgent intervention to safeguard and protect each astronomical band observable from the ground is outlined.

Read this paper on arXiv…

S. Gallozzi, M. Scardia and M. Maris
Thu, 30 Jan 20
7/65

Comments: 16 pages, 6 figures, 2 tables