Concerns about ground based astronomical observations: A step to Safeguard the Astronomical Sky - arXiv
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Concerns about ground based astronomical observations:
A step to Safeguard the Astronomical Sky
Stefano Gallozzi(1) , Marco Scardia(2) , Michele Maris(3)
February 4, 2020
arXiv:2001.10952v2 [astro-ph.IM] 3 Feb 2020
(1) stefano.gallozzi@inaf.it, in astronomic images and will be particularly
INAF–Osservatorio Astronomico di Roma negative for scientific large area images used
(2) marco.scardia@inaf.it, to search for Near Earth Objects, predict-
INAF–Osservatorio Astronomico di Brera ing and, eventually, avoiding possible impact
(3) michele.maris@inaf.it, events. Serious concerns are common also to
INAF–Osservatorio Astronomico di Trieste other wavelengths eligible for ground based in-
vestigation, in particular for radio-astronomy,
whose detectors are already saturated by the
ubiquitous irradiation of satellites communica-
Abstract tion from Space stations as well as from the
ground. Not to exclude the significant increase
This article aims to highlight the impact for in the risk of hitting into the "Kessler syn-
ground based astronomical observations in dif- drome" scenario with the deployment of all of
ferent windows of the electromagnetic spec- these satellites.
trum coming from the deployment of fleets of Understanding the risk for astronomical com-
telecommunications satellites. munity, a set of actions are proposed in this pa-
A particular attention is given to the prob- per to mitigate and contain the most dangerous
lem of crowding of circumterrestrial space by effects arising from such changes in the popu-
medium/small size orbiting objects. Depend- lation of small satellites. A dedicate strategy
ing on their altitude and surface reflectivity, for urgent intervention to safeguard and pro-
their contribution to the sky brightness is not tect each astronomical band observable from
negligible for professional ground based obser- the ground is outlined.
vations. With the huge amount of about 50,000 Keywords: Satellites constellations, ground
new artificial satellites for telecommunications based astronomical observations, ground based
planned to be launched in Medium and Low radio astronomy.
Earth Orbit, the mean density of artificial ob-
jects will be of >1 satellite for square sky de-
gree; this will inevitably harm professional as- 1 Introduction
tronomical images.
Only one of these project, Starlink@SpaceX’s, The deployment of large fleets of small satel-
was authorized by US Federal Communication lites planned or ongoing for the next genera-
Commission, F.C.C. and plans to deploy about tion of global telecommunication networks can
42,000 not geostationary satellites, which will severely harm ground based astronomical ob-
shine from the 3rd to the 7th magnitude in sky servations.
after sunset and before sun dawn. For centuries ground based astronomical obser-
All satellites will leave several dangerous trails vations have led to exceptional progresses in
1
our scientific understanding of the Laws of Na- similar size (quantified by the diameter of its
ture. Currently, the capability of ground based main mirror). As an example it took more
astronomical instrumentation is endangered by than twenty years to develop the next large
the deployment of satellite fleets of unprece- space telescope, the JWST planned for launch
dented size. in 2021, with a 6.5 meters mirror at the cost
Astronomers all over the world are concerned of the order of ten billions euros. In the mean-
for the sky coverage and light/radio pollution time the VLT, with four giant 8.2 m telescopes,
produced by artificial satellites, which repre- two Magellan telescopes with 6.2 meters mir-
sent a dramatic degradation of the scientific rors, and other telescopes of similar size entered
content for a huge set of astronomical obser- in service. The next generation of new giant
vations. ground based telescopes as the GMT with a
The same concerns have been expressed by the 25.5m mirror, the ESO/eELT with a 39m mir-
International Astronomical Union, IAU ror is expected to be putted online in about
[1] and other institutions since the sky degra- half the time required for the JSWT and with
dation is not only due to light pollution in the a cost of about one billion euros per telescope.
sky near cities and the most populated areas, As the ability of a telescope to reveal small,
but it is also due to large artificial satellite weak, far objects increases with the area of its
fleets crossing the sky producing bright parallel mirror which collects light, the sensitivity of a
streaks/trails at all latitudes. telescope increases with the square of its diam-
This paper is organized as follow: section 2 eter. So in ideal conditions, the eELT will be
describes the substantial and complementary able to collect thirtysix times the amount of
characteristic between ground based astronom- light collected by the JWST.
ical facilities and those in orbit; satellite con- Compared to a ground based telescope, a space
stellations are introduced in section 3; section based telescope has the strong advantage of ob-
4 illustrates how such constellations may affect serving the sky outside the Earth atmosphere.
ground based observations; section 5 is devoted In some bands, as an example the X rays, the
to discuss possible mitigations; conclusions are Far UV or the far IR, the atmosphere blocks
in section 6. completely the incoming radiation. So that a
ground based telescope in those bands would
be completely blind or severely limited, but
2 Ground Based and Space this is not true in other bands. As an ex-
Based Astronomy ample: in visible light our atmosphere is quite
transparent, so that to observe in visible light
The advent of space based astronomy (i.e. from space is of little advantage with respect
UVES, HST, Spitzer, Herschel, Planck to cite to the case of observing from ground, save for
just some of well known space telescopes) did the disturbance introduced by atmospheric tur-
not dismiss ground based astronomy. On bulence. However this last problem has been
the contrary ground based astronomy and largely mitigated in the last decades through
space based astronomy complement each other. a careful selection of the sites where telescopes
Without ground based observations most of are installed, and by the adoption of techno-
current space based astronomy would be use- logical innovations such as the adaptive optics.
less or impossible. The reasons for this state- A major limitation of space based telescopes is
ment are shortly outlined below. that they can not be maintained, refurbished
The effort of developing, deploying and oper- or repaired after launch. In this respect HST
ating a space based telescope is bigger, even has been a ‘unicum’ that hardly will be possible
of more than an order of magnitude, than the to repeat. The obvious consequence is that the
effort required for a ground based telescope of operational lifetime of such telescopes is lim-
2
ited by the amount of consumables which can satellites for many important purposes. Re-
be stored onboard (example coolant for the in- cently networks, known as satellite constella-
struments) and by the resilience of the instru- tions, have been deployed and are planned in
ments to the degradation induced by ageing, ever greater numbers mainly in low-Earth or-
radiations, micro meteoroids and so on. Com- bits for a variety of purposes, including pro-
pared to ground based observatories, the aver- viding communication services to underserved
age life-time of space based telescopes is of the remote areas. Until 2019, the number of such
order of a couple of decades or less. On the satellites was below 200, but that number is
contrary ground based observatories lasts for now increasing rapidly, with plans to deploy
several decades, with telescopes installed at the potentially tens of thousands of them. If no
beginning of the space era again working in a action will be put in place, several problems
profitable manner. Being impossible to replace will soon arise in Astronomical observations.
its components, space based telescopes suffer
technological obsolescence when compared to
ground based observatories. In general space 3.1 The Iridium Satellite Con-
based telescopes are too expensive to be used stellation
to validate new observing technologies, which
usually are developed on ground based tele- The Iridium satellite constellation provides
scopes first. L-band voice and data information cover-
There are strong limitations on the mass, the age to satellite phones, pagers and inte-
size, the technology which can be sent in space, grated transceivers over the entire Earth sur-
putting severe constraints on designing and op- face. The band used to provide communi-
erating space telescopes. On the contrary, we cation services are proper of LTE-Advanced
are virtually allowed to plan as large a ground and UMTS/HSDPA services and operates from
telescope as we want, provided it will not break 1452 to 1492 MHz.1
under its own weight, it will be of practical use, The constellation consists of 66 active satel-
and its cost will be sustainable. lites in orbit, required for global coverage, and
Before to conclude it is important to stress additional spare satellites to serve in case of
that the arguments presented above have not failure. Satellites are in Low Earth Orbit,
to be misused or misinterpreted as arguments LEO at a height of approximately 781km and
against space based astronomy. On the con- inclination of 86.4◦ . Orbital velocity of the
trary in the modern professional practice both satellites is approximately 27,000km/h. Satel-
kinds of astronomy are equally important, so lites communicate with neighboring satellites
that astronomers involved in ground based as- via Ka band inter-satellite links. Each satel-
tronomy are often involved in space based lite can have four inter-satellite links: one each
astronomy and vice-versa. Our aim is to to neighbors foreground and afterground in the
disprove the quite common misunderstanding same orbital plane, and one each to satellites in
that ground based astronomy can be dismissed neighboring planes to either side. These satel-
because of the advent of space based astron- 1
In Europe, the Electronic Communications Com-
omy. mittee (ECC) of the European Conference of Postal
and Telecommunications Administrations (CEPT) has
harmonized part of the L band (1452–1492 MHz), al-
lowing individual countries to adopt this spectrum for
3 What are Satellites’ Con- terrestrial mobile/fixed communications networks sup-
stellations plemental down-link (MFCN SDL). By means of carrier
aggregation, an LTE-Advanced or UMTS/HSDPA base
station could use this spectrum to provide additional
Over the past decades, considerable effort has bandwidth for communications from the base station
gone into designing, building, and deploying to the mobile device; i.e., in the downlink direction.
3
lites will cover an entire orbit around the Earth 3.3 The OneWeb Satellite Con-
within roughly 100 minutes. stellation
Is a UK project to provide global satellite In-
3.2 The SpaceX Starlink Constel- ternet broadband services to people everywhere
lation and it is composed of a constellation of about
5260 satellite displaced in a circular LEO
The US company SpaceX plans to put in orbit orbit shell of about 1,200km-altitude. It will
a very huge constellation of 42,000 satellites, transmit and receive in the Ku band.
called Starlink. This constellation is aimed There are about 6 testing satellites in orbit; in
to provide internet access. These satellites February 2020 other 34 satellites are planned
work in conjunction with ground trans-receiver to be launched from the Baikonur Site. Other
stations. A small set of Starlink satellites is launches are scheduled in 2020.
planned to be dedicated to military airforce [26]
and/or research purposes. This satellites fleet
will be displaced in three orbital shells: 3.4 Other Constellations
1. about 10,000 satellites at In the next years there could be over 50,000
1150-kilometers-altitude orbit shell new satellites encircling the Earth (at differ-
using the Ku band (from 12 to 18 GHz) ent altitudes) for various telecommunication
and Ka bands (from 26.5 to 40 GHz). purposes but mainly delivering broad band in-
ternet from Space and, considering the close-
2. about 6,000 satellites in a ness to the Earth, internet signals will be pro-
550-kilometer-altitude orbit shell, us- vided fast and with very low-latency. Table 1
ing the same Ku and Ka bands. is a non-exhaustive list of principal satellite-
constellation.
3. about 26,000 satellites in a A so large number of new self-drivng satellites
340-kilometer-altitude orbit shell us- in different low-altitude orbiting shells could
ing the V-band (from 40 to 75 GHz).2 also impact on the capability to send in the
outer space new science related missions, since
The first phase of deployment will put in orbit it would be impossible to exactly predict the
first the 550km-altitude satellites, then those at single positioning of each constellation satel-
1150km-altitude. To the first phase a second lite, so that impact risk will strongly increase
phase will follow with the deployment in or- during scientific mission launches.
bit of the remaining inner satellites at 340km-
altitude.
Because the Starlink satellites can au- 4 The impact of large satel-
tonomously change their orbits, observations lite constellations on
cannot be scheduled to avoid them.
2
ground based astronomy
The 5th generation mobile networks (28, 38, and 60
GHz) will also partially overlap with Ka and V bands.
The V band at 60 GHz was used by the world’s first The ground-based observatories with their
cross-link communication between satellites in a con- large optical telescope currently working (Very
stellation between the U.S. Milstar 1 and Milstar 2 Large Telescope, VLT [2], Large Binocular
military satellites. The 60GHz frequency band is at- Telescope, LBT [3], ...) and those in con-
tractive to secure satellite crosslinks because it allows
high data rates, narrow beams and, lying in a strong
struction (e.g. the Extremely Large Telescope,
absorption band of oxygen, provides protection against ELT [4], with a main 39-meter diameter mir-
intercept by ground-based adversaries. ror) are essential complements to astronom-
4
Figure 1: First orbital planes of Starlink satellites after the 21 January 2020 launch of 60
satellites by the Falcon-X rocket to reach the total number of orbiting satellites of 240. Star-
link@SpaceX systems will be turned on at 420 satellites, while the first broad band internet
service will be provided once ~1000 satellites will be deployed. The red arrows indicates the
Falcon9 orbiting bucket and the experimental Starlink DARKSAT, with an experimental coating
to make it less reflective, and thus impact ground-based astronomical observations less.
ical satellites, which are not affected by re- and the most populated areas (see Fig. 2), but
flections of the satellites. As introduced in it is also due to artificial satellite fleets crossing
the second section, for astronomical satellites, and scarring observations with bright parallel
missions costs and limitations on size/weight streaks/trails at all latitudes.
preclude the launch of particularly large tele-
scopes, thus the difficulty in repairing and Astronomers are extremely concerned by the
maintaining telescopes in space means that possibility that sky seen from Earth may be
the newest, most revolutionary technologies are blanketed by tens of thousands of satellites,
implemented only on ground-based telescopes. which will greatly outnumber the approxi-
Ground based telescopes are fundamental to mately 9,000 stars that are visible to the un-
astronomy and the international community aided human eye. This is not some distant
and single states have invested for these ground threat: it is already happening. As seen in
based projects in past years several tens of bil- section 3, the US private company SpaceX has
lions of dollars/euro trillions of dollars, there-already put 240 of these small satellites, col-
fore they are requested to produce high rate lectively called Starlink, in the sky and plans
of scientific results to repay the initial public to constellate the whole sky with about 42,000
investment received. satellites. Thus, together with other telecom-
munication space projects in the near future
What is really damaging such scientific results (see §1.1), in a very short term there could be
is the sky degradation. This is not only due to over 50,000 small satellites encircling the Earth
sky-glow / light pollution in the sky near cities (at different altitudes) each of them damaging
5
Constellation Name n. Satellites Altitude [km] Bands Serv.Start
SpaceX - Starlink (USA) 42,000 1150, 550, 340 Ku, Ka, V 2020
OneWeb (UK) 5,260 1200 Ku 2020
Telesat (CAN) 512 ~1000 Ka 2022
Amazon - Kuiper (USA) 3236 590, 630, 610 ? 2021
Lynk (USA) thousands ? 2023
Facebook (USA) thousands 500-550 ? 2021
Roscosmos (RU) 640 870 ? 2022-2026
Aerospace Sci.Corp. (CHI) 156 ~1000 ? 2022
Table 1: Satellite-Constellation projects comparison.
astronomical observations. the brightness of the stars in the Ursa Minor
The closeness of satellites in LEO makes them constellation. There are only 172 stars in the
more visible, and brighter in the night sky es- whole sky exceeding the expected brightness of
pecially when lighted by the Sun (e.g. satellites Starlink satellites (see Tab. 2). Higher altitude
launched by SpaceX are brighter than 99 per- LEO satellites (e.g. over 1000km-altitude) will
cent of the population of objects visible by the be visible all the night reaching approximately
Earth orbit ). the 8th magnitude.
As comparison, the current total number of
cataloged objects in Earth orbit is less than
20,000 among spacecrafts, rocket bodies, frag-
mented mission and other related debrids, so
with only the nominal Starlink fleet the to-
tal number of orbiting objects will increase of
300% (see Fig. 2 and 3).3
In the mid and long term, this will severely di-
minish our view of the Universe, create more
space debris and deprive humanity of an un-
blemished view of the night sky.
It has been considered that most of these satel-
lites will be visible to the naked eye (with
a brightness between the 3rd and 7th magni-
tude) particularly in the time after sunset and
before sunrise. Consequently they will reach
3
It has been estimated that here are over 500,000
non-cataloged pieces of space debris from the size of
one square cm (or larger) orbiting the Earth traveling
up to 17,500 mph; millions of others are untraceable,
in addition to the around 20,000 cataloged objects in
Table 2: Stars Apparent Magnitudes compar-
Earth orbit. In 1978 this scenario was predicted by D.J isons.
Kessler, [30], warning governments about the devastat-
ing cascading effect of collision-induced debris creation The most important contribution on pollution
(the so-called Kessler syndrome). The increase number of astronomical images comes from the satel-
of LEO satellites makes the creation of a dense debrids
network belt around the Earth a possible scenario with
lites in the higher orbits since the light directly
devastating consequences for the future of space explo- reflected by the Sun make them brighter dur-
ration and telecommunications too. ing the night, instead lower altitude satellites
6Figure 2: Effect of Sky-glow and cut-off angle, showing the relative impact of a luminaire’s
output contribution to skyglow. Picture taken from “Starlight: a Common Heritage”, Cipriano
Marin, IAC - ESP
Figure 3: a) Number of object in the Earth’s orbit and b) Number of artificial crossing bodies
during an observing night.
are foreseen to contribute negatively only few will be visible in the northern part of the sky.
hours after sunset and before sun dawn. It is Also the swarm of the satellites near the hori-
possible to predict the range of variability of zon will be mostly invisible due to their dis-
apparent magnitudes of the LEO satellites de- tance and atmospheric effects. It should be
pending on the position and the altitude con- noted that the "worst case" will be experienced
sidering a mean density of about 1 satellite per during the summer, in northern half of the sky,
square degree (see Fig. 4a and 4b and [12] for in the northern hemisphere, where the satellites
a whole sky simulation of 12,000 Starlink satel- will be visible during the entire night, though
lites at three different altitudes). their brightness will probably be lower than the
In Fig. 4b, illustrates how starlink orbital bright overhead passes after the sunset and be-
shells (shown in red) are illuminated by the fore the sunrise. The "best case" will be during
Sun when it is at different altitudes below the the winter, at midnight, when the sky will be
horizon. We can see that the lower the sun virtually free of any satellites, except for the
is only the more distant satellites will be illu- horizon; for details see [28].
minated. At certain stages the lowest shells Thus with 50k satellites the "normality" will
won’t be visible at all, but the higher shells be a sky crowded with artificial objects: every
7Figure 4: a) Apparent magnitude of satellites during an observing night depending on the
altitude; b) Illumination factor depending on the Sun altitude of the three orbital shells for
Starlink satellites. For OneWeb satellites the expected illumination fraction will be the same of
highest starlink orbital shell, see [28].
square degree of the sky will have a satellite and sky surveys are commonly used in search
crawling in it along the whole observing night for Near Earth Objects, NEOs, asteroids mon-
accessible and visible by astronomical cameras itoring and other related searches to guard
and not only by professional instrumentation. the Earth from potential impact events: such
It should also be noted that during nominal ser- satellite constellations could negatively impact
vice operations SpaceX expects to dismiss and on the ability to prevent and warn the whole
replace from 2,000 to 8,000 Starlink satellites humankind.
every year, disintegrating them in the lower at- The light pollution is extremely damaging for
mosphere, with all related issues, see [27] page astronomical observations at all wavelengths.
4-5 for details. To minimize the quantity of light reflected by
LEO satellites, Starlink has put in orbit an ex-
perimental version of the Starlink satellites (
4.1 Impacts on ground based op- Starlink satellite n.1130 DARKSAT, see Fig.
tical astronomy n.1) making use of a non-reflecting paint on
the body. It is not clear how this coating will
Wide-field survey telescopes will be particu-
reduce the brightness of the satellite since it is
larly damaged, by the presence of multiple sat-
not possible to cover solar panels, which repre-
urated trails within camera images:
sents 75% of the satellite reflecting surface.
• LSST [5], capable to scan and perform a If the satellite body will be inhibited to reflect
survey of the entire sky in three nights the sun light, it will absorb radiation warm-
ing too much with possibile failures, thus will
• VST [6], with its 268MegaPixels camera probably increase the risk management for the
and a FOV of 1 square degree whole fleet and make the dark-coating solution
ineffective or even counterproductive.
• Pan-STARRS [7], with its FOV of 7 square
degrees and 1.4 Giga pixels camera Moreover even if the brightness of the experi-
mental satellite would be below the naked eye
Also deep/long exposures with small-field fa- sensitivity, astronomical images will continue
cilities will be unavoidably impaired, see Fig. to see them (with resulting damage to their
5 and [12]. scientific content).
This have also a dramatic impact on our safety Thus degradation for scientific observations
because large area astronomical observations will remain high also with coating for three dif-
8Figure 5: Few Starlink satellites visible in a mosaic of an astronomical image (courtesy of NSF’s
National Optical-Infrared Astronomy Research Laboratory/NSF/AURA/CTIO/DELVE)
ferent reasons: 4.2 Impacts on ground based
radio-astronomy
1. Astronomical deep field camera images
Even with best coating and mitigation proce-
will continue to have trails in long expo-
dures to decrease the impacto on visual astro-
sures depending on the filter limiting mag-
nomical observations, what it is often omit-
nitude.
ted or forgotten is that telecommunication con-
stellations will shine in the radio wavelengths
2. Astronomical objects in the sky will be bands, observable from the ground.
eclipsed, this will probably harm time- The scientific needs of radio astronomers and
dependent (variability) studies. other users of the passive services for the al-
location of frequencies were first stated at the
3. The reflectivity of a surface depends on World Administrative Radio Conference held
the observational wavelength, so what be- in 1959 (WARC-59). At that time, the general
comes dark in one part of the spectrum pattern of a frequency-allocation scheme was:
(e.g. visible), will remains bright in other
parts of the spectrum (e.g. infrared or ra- 1. that the science of radio astronomy should
dio). be recognized as a service in the Ra-
9dio Regulations of the International space-borne radio communications is regulated
Telecommunication Union (ITU); on a collaborative international basis.
What is not widely acknowledged is that the
2. that a series of bands of frequencies
development of the latest generation telecom-
should be set aside internationally for
munication networks (both from space and
radio astronomy4
from Earth) already has a profound impact
3. that special international protection on radio-astronomical observations (at all sub-
should be afforded to the hydrogen bands): with LEO satellite fleets it is quite sure
line (1400-1427 MHz), the hydroxyl that the situation could become unbearable.
(OH) lines (1645-1675 MHz), and to In particular, low Earth orbit satellite’s spec-
the predicted deuterium line (322-329 tral windows identified to communicate with
MHz)... earth stations in the Ku (12-18GHz), Ka (27-
40GHz) and V (40-75GHz) bands will over-
Since 1959 a large number of spectral lines from lap with the nominal radio-astronomy bands
a wide variety of atoms and molecules in space and so will interfere with ground radio tele-
have been discovered, then the frequency range scopes and radio interferometers, making the
of radio astronomy now extends to at least radio detectors enter in a non-linear regime in
500 GHz. In particular frequencies of the CO the K band (18-26.5GHz) and in Q band (33-
molecule (at 115, 230, and 345 GHz), isotopes 50GHz). This fact will irreparably compromise
(at 110, 220, and 330 GHz) and the maser of the whole chain of analysis in those bands with
H2O at 22,235GHz [29], are critical to many repercussions on our understanding of the Uni-
aspects of astronomy, see also [21]. verse, or even, making the astrophysics com-
Radio astronomers have been engaged for munity blind to these spectral windows from
decades in the work of the United Nations the ground, see Fig 6.
Agency ITU to regulate the international use of There are different projects in development for
the radio frequency spectrum. Their efforts en- ground based radio-astronomy that will signif-
sured a limited number of narrow bands of the icantly overlap with telecommunication signals
spectrum received protection to allow radio as- coming from the satellites’ constellations in or-
tronomy to develop and conduct essential and bit:
unique research.
• The Next Generation Very Large Ar-
Despite the special international protection ray, ngVLA and ngVLA Long Base-
for Radio-astronomy, some sources of radio line Array, LBA [18]: located in New
frequency interference (RFI) are inescapable. Mexico, west Texas, Arizona, and north-
While radio astronomers can minimize the ef- ern Mexico. The VLA will use 6 radio-
fects of many terrestrial sources by placing bands: 2,4GHz, 8GHz, 16GHz, 27GHz,
their telescopes at remote sites, none can es- 41GHz and 93GHz.
cape from RFI generated by satellite trans-
mitters, such as those of the Iridium System, • The Square Kilometer Array, SKA
SpaceX, and others. [19], [23] will interfere with Ku satellites
communication bands.
Whilst there is legislation in place where radio
observatories are placed (e.g. at the two SKA • The Atacama Large Millimeter Ar-
sites in Australia and South Africa) to protect ray, ALMA [22], the world-leading mm
the telescopes from ground-based radio inter- and sub-mm observatory built in At-
ference at those frequencies, the use of air and acama, Chile, with enormous expenses
4
These bands should lie at approximately every oc-
spent by a broad international community,
tave above 30 MHz and should have bandwidths of facility that has brought us many signifi-
about 1 percent of the center frequency. cant discoveries and played a crucial role
10Figure 6: Spatial resolution versus frequency set by the maximum baseline of the ngVLA
compared to other existing and planned facilities, see [18].
in the global system of EHT (first image 5 How to protect the Astro-
of BH ever, published in April 2019), has
its Bands 1, and 2+3 exactly in the poten-
nomical Sky?
tially polluted part of the spectrum.
To answer this question, we must remember
some International Conventions and Treaties.
To aggravate the matter, with the current tech- The Preamble of the World Heritage Con-
nological development, the planned density of vention holds that “the deterioration or disap-
radio frequency transmitters is impossible to pearance of any item of the cultural or natural
envisage. In addition to millions of new com- heritage constitutes a harmful impoverishment
mercial wireless hot spot base stations on Earth of the heritage of all the nations of the world”
directly connected to the about 50,000 new This protection appears again in the 1994 Uni-
satellites in space, will produce at least 200 versal Declaration of Human Rights for Future
billion of new transmitting objects, according Generations:
to estimates, as part of the Internet of Things Persons belonging to future genera-
(IoT) by 2020-2022, and one trillion of objects tions have the right to an uncontam-
a few years later. inated and undamaged Earth, includ-
ing pure skies; they are entitled to
Such a large number of radio-emitting objects its enjoyment as the ground of human
could make radio astronomy from ground sta- history of culture and social bonds
tions impossible without a real protection made that make each generation and indi-
by countries’ safe zones where radio astronomy vidual a member of one human family.
facilities are placed.
The UNESCO has undertaken activities for
We wish to avoid that technological develop- the safeguarding of cultural heritage related to
ment without serious control turns radio as- astronomy under the “Astronomy and World
tronomy practice into an ancient extinct sci- Heritage” project launched by the World Her-
ence. itage Centre in 2003. This concept was taken
11up again by UNESCO in 2005 as: Within the framework of Interna-
The sky, our common and universal tional Law and State based legal in-
heritage, is an integral part of the struments, Protection of Starlight
environment perceived by humanity. could then be implemented in the
Humankind has always observed the same manner:
sky either to interpret it or to un- 1. Reaffirms the sovereign rights and
derstand the physical laws that gov- responsibilities, towards the Inter-
ern the universe. This interest in as- national Community, of each State
tronomy has had profound implica- for the protection of its own cul-
tions for science, philosophy, reli- tural and natural heritage;
gion, culture and our general con- 2. Calls upon the International Com-
ception of the universe. munity to provide all the possible as-
sistance needed to protect and con-
This in turn led to the following concepts:
serve the cultural and natural her-
astronomical observations have pro-
itage of Starlight;
found implications for the develop-
3. Invites the authorities of States
ment of science, philosophy, religion,
to take appropriate measures in or-
culture and the general conception
der to safeguard the cultural and
of the universe. . . discoveries of
natural heritage of Starlight;
astronomers in the field of science
4. Further invites the States to co-
have had an influence not only on
operate with UNESCO, the World
our understanding of the universe
Heritage Committee, the UNWTO,
but also on technology, mathemat-
and the Starlight Initiative with a
ics, physics and social development
view to ensuring effective protec-
in general. . . the cultural impact of
tion of its cultural and natural her-
astronomy has been marginalized and
itage in Starlight.
confined to a specialized public.
Having established these rights under interna-
These protections for Starlight are necessary as tional law, the conclusion is that there exist
the impact that Starlight has held on human- duties for both States and international orga-
ity has been expressed in works of religion, art, nizations to protect the World Heritage Right
literature, science, philosophy, business, and to Starlight, as well as, their duties to foster
travel. the rights of travelers, hosts, and providers of
Enforcement of the Right to Starlight: travel to enjoy this Starlight “property inter-
International law enforces interna- est” that belongs to all humanity. The existing
tional legal obligations, including legal instruments demonstrate the protection
property interests. Here, World for the Right to Starlight, but it is the States
Heritage is the property of all hu- that act as custodians of World Heritage that
mankind, and while there may be pro- are charged with ensuring these rights are en-
tective laws, enforcing this is an- forceable, and in turn made available to all of
other matter, as only States can humanity.
sue other States under this type of
international treaty. A State is
responsible for the activities that 5.1 On the legal side
occur within its jurisdiction –
whether they are authorized or SpaceX private company has received permis-
unauthorized. sion from many USA government agencies (e.g.
Federal Communication Commission, FCC) to
Thus: launch these satellites into orbit. So there
12could be a legal claim, within the US legal sys- approve. So in the most basic sense,
tem, to halt the progress of Starlink. SpaceX’s satellites displacement autho-
Also, as it turns out, according to the Outer rization would be unlawful, see [31].
Space Treaty and its progeny, there are no pri-
vate companies operating in outer space, but 2. Sue in court for lack of jurisdiction and
only governments can operate in outer space. jurisprudence of US FCC to authorize pri-
And the legal process is that the state govern- vate not geostationary satellites over other
ment, this time the USA government, is legally states and nations.
responsible for all objects sent into outer space
that launch from USA borders. That means, 3. Sue in the International Court of Jus-
that it is the USA government that is respon- tice, ICJ the USA government to put on
sible for the harm caused by its corporation, hold further Starlink launches to quan-
Starlink, sending objects into orbit that cause tify the loss of public finances in damag-
harm. ing national and international astronomi-
So under this international law, any coun- cal projects.5
try that suffers harm by Starlink can sue the
United States government in the International
Court of Justice in the Hague. The harm here 5.2 From the astronomers’ side
is damage to our cultural heritage, the night
An international appeal/petition from as-
sky, and monetary damages due to the loss of
tronomers was launched in January 2020
radio and other types of astronomy. For the
and, at the time of writing, thousands of as-
scientists, the owners of the observatories have
tronomers involved with astronomical observa-
a legal argument that they have and will con-
tories and facilities, have subscribed the ap-
tinue to lose money spent for their research
peal, see [25]. Another open letter has
based on Earth based observatories. Further-
been prepared reguarding same concerns on the
more, Universities that own the observatories
are state owned universities, so it is the gov- 5
Though there are no international law that re-
ernment that owns the observatories that have strict mega constellations, to deploy and dispatch mega
lost financially because of their interruption of constellations an international agreement among states
is needed, since satellites can not be located only
study of the night skies.
over a single state (e.g. USA) but, being in LEO,
So it is essential that a government, like Chile, they move around the globe passing over different
Italy or France, sues the USA in the Interna- states/nations/continents. This is a lack of jurisdic-
tional Court of Justice. tion of FCC authorization. In particular the Interna-
tional Court of Justice, ICJ, can be called into question
If no national or international entity will whenever there is a dispute of international jurisdic-
stop this displacement the right of the tion or between member states of the United Nations
private company SpaceX will become on the basis of international norms, treaties and / or
acquired at the beginning of March 2020. their violations. In the beginning of chapter 5 it was ex-
plained how the World Heritage Convention regarding
How should the international astronomical the “right of night sky / starlight” belongs to universal
community mobilize in order to stop further human rights and so no state can decide to contravene
Starlink launches? this convention if it interferes with the enjoyment of
that right for other states. The pretext for appeal-
1. Sue in court for luminous pollution not ing to the United Nations and the International Court
taken into account by US FCC: The FCC’s of Justice (ICJ) is the loss of scientific value of the
lack of review of these commercial satel- investments made for ground based projects by each
lite projects violates the National Environ- state (damaged by SpaceX). Each damaged state, be-
ing damaged as conseguence of a violation for an in-
mental Policy Act, NEPA, which obligates ternational treaty, the issue cannot be settled with a
all federal agencies to consider the envi- simple money compensation, but with an inhibition of
ronmental impacts of any projects they the damage before the same occurs (and not after).
13satellites constellations deployment for the fur- 6. to limit and regulate the number of
ther space missions and to raise awareness to telecommunication satellite fleets to the
US Senate, and US commisisons on the possi- “strictly necessary number” and to put
bility that occurs the Kessler Syndrome, which them in orbit only when old-outdated
is a realistic scenario with all these orbiting ob- technology satellites are deorbited, accord-
jects, see [32]. ing to the Outer Space Treaty (1967) - the
Requests from the astronomical community Art IX [8], and the United Nations Guide-
to governments, institutions, and agencies all lines for the Long-term Sustainability of
around the world are: Outer Space Activities (2018) – guide-
line 2.2(c) [9], requiring the use of outer
1. to be committed to provide legal protec- space be conducted “so as to avoid [its]
tion to ground astronomical facilities in harmful contamination and also adverse
all of the available observation electromag- changes in the environment of the Earth”
netic windows. and [. . . omissis...] risks to people, prop-
erty, public health and the environment
2. to put on hold further Starlink launches associated with the launch, in-orbit oper-
(and other projects) and carry out an ac- ation and re-entry of space objects”.
curate moratorium on all technologies that
can negatively impact astronomical space
based and ground based observations, or
6 Conclusions
impact on the scientific, technological and
Avoiding damages in astronomical ground
economic investments that each State en-
based observations arised from the displace-
gages in astrophysical projects.
ment of satellite constellations is absolutely
mandatory for safeguarding not only the eco-
3. to put in place a clear evaluation of risks
nomic and scientific investment, committed by
and predictive impacts on astronomical
international institutions and single nations,
observatories (i.e. loss of scientific and
but also to continue efficiently to monitor pos-
economic value), giving stringent guide-
sible impact events to guard and alert the hu-
lines to private individuals, societies and
mankind.
industries to plan satellite investments
without clearly understanding all of the All of these requests come from the heartfelt
negative effects on outstanding astronom- concern of scientists arising from threatens to
ical facilities. be barred from accessing the full knowledge of
the Cosmos and the loss of an intangible as-
4. that the US Federal Communications set of immeasurable value for humanity. In
Commission (FCC) and any other national this context it is absolutely necessary to put
agency be wary of granting permission to in place all possible measures to protect the
ship non-geostationary low-orbit satellites night sky right also on the legal side as stated
into orbit or alternatively to limit the au- by the Universal Declaration of Human Rights
thorization of only satellites being above for Future Generations.
the airspace of the “home country”. To ensure this safeguard action it would be de-
sirable to adopt contingent and limiting reso-
5. to demand a worldwide orchestration, lutions to be ratified as shared international
where national and international astro- rules, which must be adopted by all space
nomical agencies can impose the right of agencies to ensure protection for astronomical
veto on all those projects that negatively bands observable from the ground. All of this
interfere with astronomical outstanding to continue to admire and study our Universe,
facilities. for as long as possible.
14In the meanwhile all private displacement of [9] Committee on the Peaceful Uses of
satellites constellation project must be put on Outer Space, “Guidelines for the
hold; every “national” authorization to launch Long-term Sustainability of Outer
not geostationary LEO satellite fleets must be Space Activities ”:
withdrawn and avoided as well. https://www.unoosa.org
"One person’s freedom ends where another’s
begins". The public authorities (of every state) [10] Simulated prediction of “only”
are entitled (and obliged) to enforce regula- 12k Starlink satellites positions in
tions, which take care that the above statement the sky: www.youtu.be/LGBuk2BTvJE
comes true. The right to see the sky in natural
state belongs to our rights and freedoms alike [11] Simulated prediction of “only”
the right to breath unpolluted air, drink clean 12k Starlink satellites naked eye view
water or sleep in a quiet environment during of the sky:
the night. www.youtube.com/9hQfKd9kfA
[12] Visualization tool to find, plot
References and search satellite orbits:
https://celestrak.com/orbit-viz
[1] International Astronomical Union,
IAU statements: www.iau.org/ann19035 [13] Phil Cameron, “The right to
Starlight Under International Law”
[2] ESO Very Large Telescope:
www.eso.org/paranal-observatory/vlt [14] Starlight Initiative “Declaration
in defense of the night sky and the
[3] Large Binocular Telescope, LBT: right to starlight”:
http://www.lbto.org/ starlightdeclaration
[15] Marian Cipriano, “Starlight: a
[4] ESO Extremely Large Telescope,
common heritage”, Published online by
E-ELT: www.eso.org/elt
Cambridge University Press: 29 June
2011
[5] Large Syhoptic Survey Telescop,
LSST: Vera_C._Rubin_Observatory
[16] Marin, C., and Jafar, J. (eds)
2008,Starlight: A common
[6] ESO VLT Survey Telescope: Heritage(Tenerife: Instituto de
surveytelescopes/vst As-trof´ısica de Canarias)
[7] Pan-STARRS Telescope: [17] Starlight Scientific Committee
panstarrs.stsci.edu Report 2009,Starlight Reserve Concept:
http://www.starlight2007.net
[8] United Nations Office for Outer
Space Affairs, “Treaty on Principles [18] A.J. Beasley, E. Murphy, R.
Governing the Activities of States in Selina, M. McKinnon & the ngVLA
the Exploration and Use of Outer Project Team, “The Next Generation
Space, including the Moon and Other Very Large Array (ngVLA)” NRAO
Celestial Bodies”:
introouterspacetreaty.html A citation: [?]
15[19] Square Kilometer Array, SKA: [30] Donald J. Kessler, Burton G. Cour-
https://www.skatelescope.org Palais, “Collision frequency of artificial satel-
lites: The creation of a debris belt”, doi:
[20] Avinash A. Deshpande and B. M. https://doi.org/10.1029/JA083iA06p02637
Lewis, “Iridium Satellite Signals: A [31] Ramon J. Ryan, Note, The Fault In
Case Study in Interference Our Stars: Challenging the FCC’s Treatment
Characterization and Mitigation for of Commercial Satellites as Categorically Ex-
Radio Astronomy Observations”, DOI: cluded From Review Under the National En-
10.1142/S225117171940009, vironmental Policy Act, 22 VAND. J. ENT. &
arXiv:1904.00502 [astro-ph.IM] TECH. L. (forthcoming May 2020)
[32] David Dubois, NASA “Open Letter
[21] Committee on Radio Frequencies to FCC, US Senate and Commissions and
Board on Physics and Astronomy SpeceX“, OpenLEtterforFCCandNASA
Commission on Physical Sciences,
Mathematics, and Applications National
Research Council “VIEWS OF THE
COMMITTEE ON RADIO FREQUENCIES
CONCERNING FREQUENCY ALLOCATIONS FOR
THE PASSIVE SERVICES AT THE 1992 WORLD
ADMINISTRATIVE RADIO CONFERENCE “
[22] Atacama Large Millimeter Array,
ALMA: https://www.eso.org
[23] SKA statements on satellites
contellations:
ska-statement-on-satellite-constellations
[24] PATRICIA COOPER, “SATELLITE
GOVERNMENT AFFAIRS SPACE EXPLORATION
TECHNOLOGIES CORP. (SPACEX)”:
https://www.commerce.senate.gov
[25] APPEAL BY ASTRONOMERS:
https://astronomersappeal.wordpress.com
[26] Starlink testing encrypted internet
form military US Air Force purposes:
https://www.reuters.com/article
[27] Starlink APPLICATION FOR AP-
PROVAL FOR ORBITAL DEPLOYMENT
AND OPERATING AUTHORITY FOR THE
SPACEX NGSO SATELLITE SYSTEM:
Legal-Narrative.pdf
[28] Starlink simulations from deepskywatch:
http://www.deepskywatch.com
[29] Volvach et al 2019, “An Unusually Power-
ful Water-Maser Flare in the Galactic Source
W49N”, doi: 2019ARep...63..652V/doi:10.1134
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