Safeguarding the Astronomical Sky Foundation (SAS Foundation)

It is a non-lucrative ONG Foundation as a physiological and natural continuation of the Appeal by Astronomers movement.

(request information to join the foundation)

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CF: 96481380580

The appeal received many adhesions (more than 2000), but we found ourselves unable to include the more strictly amateur associations, which are also heavily penalized by these deployments.
Fortunately, a legal action called Healthy Heavens Trust Initiative has started few months ago, which is currently suing the American FCC in American federal courts of justice.

To join and support requests from these lawyers, as people interested in safeguarding the night sky, we need to have a legal representation for astronomers to face off in these judgments; such representation should be structured and cohesive (not only therefore professionals, but also amateur realities and even environment associations interested).

So it became necessary to establish a non-profit-making NGO-type Association/Foundation, to give a clear reference to all environmental protection associations, professional and amateur astronomical associations, individual astronomers and all astronomical bodies and societies, who wish to join, in a totally spontaneous way, even in later time, for the preservation of the Astronomical Sky and to have a common discussion container and legal recognition for all these actions, in an international contest level, that may ensue.

Our Mission

Ground-based astronomical observations will be severely damaged by the ongoing deployment of large fleets of satellites to ensure the functioning of future telecommunications technologies.

For centuries, ground-based astronomical observations have brought exceptional advances in our scientific understanding of the Laws of Nature. Currently, the capabilities of ground-based astronomical instrumentation are endangered by the persistent deployment of fleets of telecommunications satellites.

Through this international appeal and following up on the same concerns expressed by the International Astronomical Union, IAU [1] and other institutional subjects, we raise a series of formal requests regarding greater protection and safeguarding for professional astronomical observations from the ground, guaranteeing to astronomers, the right to observe a sky free from sources of light and artificial pollutants.

Specifically, the adherents of this foundation (environmental association, individual professional or amateur astronomers, astronomical institutions and national astronomical societies), wish to express their concern and their opposition concerning the coverage of the sky produced by artificial satellites, which dramatically risk to degrade the scientific content of a wide range of astronomical observations.

In fact, there is not only the light pollution of the sky due to the dispersion of light from the cities and the most populated areas of the planet, but also due to the fleets of artificial satellites, which cross and irremediably mark the observations with very bright parallel streaks / trails. at all latitudes.

Many astronomers are extremely concerned about the possibility that the Earth could be covered by tens of thousands of satellites, which will greatly exceed the approximately 9,000 stars, which are visible to the naked eye. Unfortunately this is not a distant threat or the prospect of a distant future, but it is already happening now. The American private company SpaceX has already put 180 of these small satellites, called Starlink, in the sky and plans to constellate the entire sky in total with about 42,000 satellites (at three different altitudes: 340km, 550km and 1150km). Therefore, together with other telecommunication space projects planned for the near future (e.g. OneWeb, Samsung, Telesat, Amazon, Lynk and Facebook, Roscosmos, CASC etc.), more than 60,000 small satellites could be positioned in orbit, which will orbit the Earth. at different altitudes with different objectives related to the telecommunications industry and which will mainly provide satellite Internet.

These new satellites are small, mass-produced and will orbit very close to Earth, providing a fast Internet connection with low-latency signals. But this proximity (~ 340Km altitude), when illuminated by the Sun, will also make them more visible and brighter in the night sky (in fact, the current 800 Starlink satellites are already brighter than 99 percent of the population of objects visible from terrestrial orbit ), see [12].

It should be noted that the number of artificial objects currently cataloged (and visible) in the sky does not exceed the total number of 20 thousand, including functioning objects and floating debris, so with Starlink satellites alone this total number will at least triple.

In the medium and long term, this will drastically reduce our view of the Universe, create more space debris and deprive humanity of a pristine view of the night sky. It has been calculated, [12], that many of these satellites will be visible to the naked eye (with a brightness between the 3rd and 7th apparent magnitude, i.e. reaching the brightness of the stars in the constellation Ursa Minor and exceeded in brightness by only 172 stars in the whole sky!). They will be extremely brighter in the hours immediately following the sunset and in any case, with 50 thousand satellites, the “normality” will be a sky crowded with artificial objects (a satellite in each square degree of sky, which will cause crawls, frustrating and compromising the observations for the whole the night in particular for naturalistic and astronomical photography and professional medium-wide field instruments).

Although observations with wide-field telescopes (for example LSST [2] or VST [3] or Pan-STARRS [4], …) will be the most affected, even deep and low-field exposures will be damaged, see image and [7], also because during the twilight the calibration images are acquired which will be the most affected and damaged by the phenomenon, nullifying the possibility of obtaining scientific images calibrated during the night.

Another relevant issue concerns the impact on the security of our planet, since large-field astronomical observations / surveys of the sky are commonly used in NEOs (Near Earth Objects) monitoring / research programs, it would be more problematic if not impossible to identify and monitor the objects potentially at risk of impact for the Earth: with these satellite constellations the ability to prevent and / or prepare humanity for a possible catastrophic event from impact with objects may be compromised.

This light pollution is extremely harmful for astronomical observations at all wavelengths.

Visual brightness mitigation techniques for satellites proposed by involved companies have been proved inadequate and have only helped to buy time in order to continue to send more than a hundred satellites into orbit per month. These proposed mitigation techniques did not sufficiently decrease the brightness of the satellites in orbit, which is still too high for professional astronomical ground based observations (see [12]). Furthermore, the degradation to scientific observations will remain high for two further reasons:

  1. the stars and other objects in the universe will still be eclipsed, thus altering the timing in the variability studies, and
  2. the reflectivity of the satellite surface necessarily depends on the observing wavelength, so what becomes dark in one part of the spectrum (for example the visible) remains bright (or shines) in other parts of the spectrum (for example infrared or radio ); moreover, a darker surface also means greater capture of solar heat with consequent overheating of the satellite body and consequent re-radiation in the IR.

It should also be noted that such a fleet of non-geostationary low-orbit satellites provides, at nominal operating speed, a replacement rate of from 2000 to 8000 Starlink satellites per year, which would be irremediably left to disintegrate in the lower earth’s atmosphere, risks and consequences of the case, without to mention the problems inherent in any collisions that would drastically increase space debris, with the not remote possibility of establishing a chain reaction , called Kessler’s syndrome (see [13]).

It is also important that the development of the latest generation telecommunication networks (both from space and from Earth), already profoundly influences radio astronomy observations (in all observational sub-bands): with the LEO satellite fleets it is feared that the situation will become unbearable. One of the most important radio astronomy facilities under construction, the SKA (Square Kilometer Array) has already estimated the negative impact deriving from Radio Interference coming from satellites, which, although they can be reduced and mitigated, in some bands will end up totally covering the possibility of performing astronomical observations, totally nullifying all the investments made to reveal the astronomical sky at these frequencies of the electromagnetic spectrum, see [11].

In particular, the spectral windows of satellites in low earth orbit designated to provide services and communicate with ground stations in the Ku (12-18 GHz), Ka (27-40 GHz) and V (40-75 GHz) bands will inevitably overlap. to the nominal bands of radio astronomy and therefore will interfere with radio telescopes and radio interferometers on the ground, some of which are already entering a non-linear regime (i.e. they are saturated) in the K band (18.26.5 GHz) and in the Q band (33-50 GHz). This phenomenon constantly compromises (and will compromise even more) the entire chain of analyzes in those bands with unimaginable repercussions on our understanding of the Universe, or even, by making the astrophysics community blind in these spectral windows.

Compounding the matter, with current technological development, it is impossible to predict exactly the planned density of radio frequency transmitters: the millions of new wireless base stations, commercial hot spots on Earth connected directly to future> 60,000 new satellites in space, will produce, according to estimates, at least tens of millions of new SRBs on the gorund supporting more than 200 billion new transmitting objects in the context of the Internet of Things (IoT) by 2020-2025 and a few trillion objects just a few years later.

Such a large number of objects emitting into the radio could make radio astronomy impossible from terrestrial stations without real protection, creating real areas of respect in the countries where radio astronomy structures are located.

In essence, we would like to prevent technological development without serious control from transforming the practice of radio astronomy into an ancient, extinct science.



[2]  https://www.lsst.org





[7]  Simulazioni di come “soli” 12mila satelliti Starlink popoleranno il cielo stellato: e

[8] Tool di visulizzazione delle orbite dei satelliti ricercati:

[9] Comitato di Tutela e Salvaguardia dell’ Ambiente ONLUS sito in Monte Porzio Catone (RM):

[10] Appello Internazionale degli Astronomi, “Appeal by Astronomers”:

[11] SKA Assessment on Satellite Constellations:

[12] Anthony Mallama, 2020 and 2021: , , ,

[13] Donald J. Kessler, Burton G. Cour-Palais, “Collision frequency of artificial satellites: The creation of a debris belt”, doi:

Our Foundation

Documents and related informations about the SAS Foundation can be found here:

Join SAS Foundation

To join the SAS Foundation – Fondazione SAS, please contact US
v. Santa Lucia, 64 , Fonte Nuova (RM) 00013

Stefano Gallozzi – +39 – 0694286453

Fiscal/Tax Code: 96481380580

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