Subject: SETI public: ASTRONOMERS SOUND WAKE-UP CALL ON LIGHT AND RADIO POLLUTION OF THE SKIES
Date: Wed, 16 Aug 2000 15:20:39 -0400
Subject: Astronomers sound wake-up call on light and radio pollution
Date: Wed, 16 Aug 2000 13:55:27 GMT
From: Andrew Yee
Organization: UTCC Campus Access
INTERNATIONAL ASTRONOMICAL UNION
XXIVth GENERAL ASSEMBLY, MANCHESTER, UK
7 - 18 August 2000
>From Jacqueline Mitton (Meeting Press Officer)
phone: +44 (0)1223 564914
Phone contact 7 - 16 August [Meeting Press Room]
+44 (0)161 275 7832
+44 (0)161 275 9458
+44 (0)161 275 9499
Mobile phone 07770 386133
Date released: 16 August 2000
* * * * * * * * * * * * * * * * *
CONTACTS FOR THIS RELEASE:
Dr Malcolm G. Smith,
Cerro Tololo Interamerican Observatory, Chile
Phone (after 21st August): +56 51 205 217 FAX +56 51 205212
Dr John Mason, UK Campaign for Dark Skies
Phone (mobile): 07901 890061
Dr Jim Cohen, Jodrell Bank Observatory
Phone +44 (0)1477 571321
* * * * * * * * * * * * * * * * *
ASTRONOMERS SOUND WAKE-UP CALL ON LIGHT AND RADIO POLLUTION OF THE SKIES
Mankind will lose its view of the stars altogether -- unless we learn very soon to shine
our light onto the ground, where we need, instead of into the night sky.
Astronomers at the International Astronomical Union (IAU) General Assembly in Manchester
(UK) have sounded a wake-up call for everyone on the planet Earth.
In 1999, the IAU held a Symposium on 'Preserving the Astronomical Sky', which was organized jointly with the Committee on Space Research
(COSPAR) and the United Nations Office of Outer Space Affairs in parallel with the UN
conference UNISPACE III in Vienna. The ongoing urgency for action was re-inforced in
Manchester this week.
'Light pollution' affects everyone, not just professional observatories. An average person
in the countryside away from city lights can see several thousand stars in the sky. Bit
by bit, Europe is losing this view of the heavens as we add more and lamps, and waste
energy by sending the light uselessly into the sky. Thousands of millions of pounds worth
of energy are tossed upwards into the European sky each year -- instead of down onto the
ground which we want to illuminate.
Dr Malcolm Smith, Director of the Cerro Tololo Interamerican Observatory in Chile, issued
this challenge. "Look around your city or town. See how many street lamps allow plenty of
light to shine upwards. Count how many stars you can see. If you are old enough to remember how the sky looked
30 years ago, could you see the Milky Way then? Can you now?"
"Bit by bit, without realizing, we are all losing a direct connection with the universe"
commented Dr Smith. "Not only that, light pollution is one of the most rapidly increasing
alterations to the natural environment created by humans. Reported adverse effects of this
fog of artificial light involve plants and animals as well as humankind. Human culture,
from philosophy to religion, from art to literature and science, has always developed in
relationship with the night sky and the universe beyond. Are we going to deprive future
Astronomer Pierantonio Cinzano from Padua, Italy and his colleagues have been using
measurements from satellites looking down at the Earth and measure the light shining upwards
from the world's towns and cities. Some of his maps showing the serious extent of light
pollution can be found on his home page, at
Large areas in and near cities are already very seriously affected. Good lighting design
can save a third or more of the cost of public lighting. Better lighting means less energy
is needed and pollution from unnecessary power stations can be reduced.
Preserving Dark, Starlit Skies
There are still pristine, remote, dark-sky sites where astronomers construct huge telescopes
to reach out to the edges of the universe. The most famous of these special sites are in
Hawaii, Chile and the Canary Islands.
Even in these places, city lights can be seen. A great effort is being made to protect these
sites and to avoid the situation that has already affected most of Europe by obtaining
legislation to control the wastage of light from cities and towns near these special regions.
Dr Smith spoke about the success in a town in Chile near the Cerro Tololo Observatory which
is saving 40% of its former annual electricity bill, uses its starlit sky to attract amazed
tourists from urban areas in Europe and the USA, and uses its Municipal Observatory to
educate local school children in the need to preserve this natural treasure of mankind.
Radio interference problems too
Also at the meeting, radio astronomers discussed issues relating to the interference they
encounter when using large radio telescopes. Mobile telephones, television, satellites and
airport radars are all essential to modern life but they create a noisy radio environment
that makes it very difficult to make sensitive astronomical measurements of quasars,
pulsars, black holes and the cosmic microwave background. As an example, the tiny amount of
energy transmitted by a mobile phone could easily be picked up by the giant 250-foot radio
dish at Jodrell Bank -- even if the phone were on Mars!
Radio astronomers are working with the regulatory authorities to reserve slices of the radio
spectrum for receiving natural signals from the universe amid the cacophony of modern life.
They are also seeking to establish 'international radio quiet zones', preserves with special
regulations rather like national parks. Such a zone might well be the site of a huge
square-kilometre array of radio telescopes now being proposed by the world's radio astronomers.
Information and education on light pollution
Much of the energy wasted as light pollution is produced because people do not think about
where the light goes when installing outside fixtures. To help explain more clearly the
issues involved, the International Dark-Sky Association (IDA) has set up an education working
For more information, see this URL: