8 Scientific American, May 2020
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COMMENTARY ON SCIENCE IN
THE NEWS FROM THE EXPERTS
Illustration by Martin GreRonald Drimmel is a research astronomer from
the U.S. currently living in Italy and working at INAF,
the Italian National Institute of Astrophysics.The company SpaceX has already launched hundreds of its Star-
link satellites, with plans to put as many as 42,000 of them in Earth
orbit. Its goal is to provide high-speed Internet to billions of peo-
ple. Moving toward that kind of access is laudable and important,
but it comes at a cost. Glittering with reflected sunlight, these first
orbiters, sent up in the past year, are brighter than 99 percent of
the 5,000 or so other satellites now circling Earth, and obviously
there are going to be a lot more [see “Satellite Surge,” on page 68].
This proliferation is bad for astronomy: the probability of a Star-
link satellite crossing a telescope’s field of view and ruining an
observation will be quite high near sunrise and sunset, when the
objects are most brightly illuminated. For that reason, more than
1,800 of my fellow astronomers have signed a petition calling for
governments to protect the night sky from this incursion.
This artificial mega constellation, and others being planned,
will impact more than astronomy. The current crop of Starlink sat-
ellites is also easily visible to the naked eye in a moderately dark
sky, and ultimately more than 100 moving points of light could be
observable overhead near dawn and dusk from any point on the
planet. They would then be about as numerous as the brightest
stars that are easily seen above the horizon—the same stars used
to trace the constellations.
Humanity is a mix of cultures that originated in diverse places,
with diverse histories, but virtually all of them have stirring or cau-
tionary stories inspired by that same star-studded celestial dome.
Are we about to lose something that has intangibly bound us
together, a common experience that has played its part in making
us one human family, in exchange for a modern convenience?
In response to protests, SpaceX has promised to address the
visibility problem by, for example, applying experimental coat-
ings—essentially painting the satellites black—but the company’s
aggressive launch schedule remains unchanged. And the satellites’
illuminated surfaces are mostly their solar panels—exactly the part
that cannot be painted over.
Unfortunately, at present no regulations govern how bright a
single satellite can be, let alone thousands of them together. It has
been suggested that the Federal Communications Commission’s
working assumption that satellites have no significant impact on
the environment could be challenged in court, but even then, one
nation’s laws do not hinder another country’s launches. Space lit-
erally has no borders, and the sky will need to be protected from
orbital illumination at an international level.
UNESCO maintains a registry of World Heritage sites—places
of unique and outstanding cultural or natural value to humanity—
and is dedicated to their preservation. For some of these locations,
such as the Namib Sand Sea and Gran Canaria’s Risco Caído, their
view of the night sky is a defining characteristic making them wor-
thy of World Heritage status. Unfortunately, under the World Her -
itage Convention, the UNESCO registry is limited to specific terri-
tories, and the sky is attached to no place in particular. So although
UNESCO has declared the sky part of humanity’s universal heri-
tage, it seems that the unique quality that makes that sky impor-
tant to all of us excludes it from being protected. Given the plane-
tary consequences, we hope that the United Nations will find a
way to think outside of the box to save the sky for everyone.
Until now the dark sky needed no protection. Beyond human
reach, it was our unobstructed window on the universe, an expanse
unreachable and unchangeable. The transcendent beauty of a star-
filled sky reminds us, as it did our ancestors, that we and our prob-
lems are small and that part of what makes us human may lie in
our ability to recognize and admire the wonder and beauty of a
universe larger than us—yet of which we are a part. The use of
space as a common resource, by satellite operators in particular,
should not destroy our only window on our world.
When I was growing up in Montana, it was a game to be the
first to find a moving satellite among the host of stars in the night
sky. Soon it could be a game to recognize the constellations behind
a swarm of moving points of light. Astronomy will survive; I am
much more afraid that we are all about to lose the very thing that
inspired me to become an astronomer.JOIN THE CONVERSATION ONLINE
Visit Scientific American on Facebook and Twitter
or send a letter to the editor: [email protected]Preserve
the Night Sky
Thousands of new satellites could ruin
a view that has inspired and connected
billions of people throughout history
By Ronald Drimmel