"Technological Fog" May Cut Off Humans
From Rest of Universe, Astronomers Warn
Humans may cut themselves off from valuable new knowledge about the rest of the universe in a few years by enveloping the Earth in a fog of light and radio emissions, an international group of astronomers warned today.
Astronomical research, which has strongly contributed to human progress for thousands of years, now is under threat from activities in space and on the ground, according to the conclusions of a special environmental symposium of the International Astronomical Union (IAU) attended by scientists from 25 countries. The symposium, "Preserving the Astronomical Sky," was held July 12-16 at the United Nations facilities in Vienna, Austria.
"The threats to astronomy not only jeopardize our ability to gain
important new scientific knowledge by studying the universe, but also will
increasingly affect other human activities," said Dr. Johannes Andersen,
General Secretary of the IAU. "In particular, outer space, once a pristine
environment, is rapidly becoming overexploited and polluted," Andersen
The symposium participants called for international cooperation to reduce the threats of light pollution, radio interference and space debris. "These problems are global in scale and effect, and long-term in nature. International efforts are needed to resolve them, as the UN already has done for the oceans and the Antarctic continent," Andersen said.
Specifically, the astronomers reported that:
"Wasted light" spilled into the night sky has made much of the world unsuitable for astronomical research. In addition, this problem costs billions of dollars that otherwise could be spent for more productive uses. One report presented at the symposium, showed, for example, that wasted light measured from space costs at least USD $720,000 annually in Vienna, $2.9 million in London, $4.2 million in Washington, D.C., and $13.6 million in New York City. The solution is to use good outdoor lighting techniques that not only protect the astronomical sky but also improve nighttime visibility, safety and security as well as save the money now used to produce the wasted light - a true win-win situation.
Radio signals from satellites and airborne platforms now threaten
our ability to study the extremely faint radio emissions from celestial
objects. This imperils radio astronomy, which has revolutionized our understanding
of the universe in the past half-century, including the discovery of pulsars,
quasars and the radio-emitting "afterglows" of gamma ray bursts. Radio
astronomers were the first to suffer from interference such as that coming
from globe-girdling systems of communication satellites that cannot be
avoided, even in the most remote parts of the world. They pointed out that
radio telescopes are so sensitive that a hand-held wireless telephone placed
on the Moon would be one of the "brightest" objects in the radio sky. However,
others now are beginning to feel the effects, including users of navigational
and environmental-studies satellites. With proper engineering techniques
and reasonable regulation, the interference problem can be controlled at
marginal cost, allowing astronomers to continue studying the
universe and others to use radio communication facilities. The astronomers also called for the establishment of regions on the Earth to be designated radio-quiet zones" where the most important radio observatories of today and tomorrow can be protected from interference. The science ministers of the Organization for Economic Cooperation and Development, meeting in Paris
last month, underlined the urgency of this problem. They agreed to establish a high-level task force to develop long-term solutions that will safeguard both humankind's radio windows on the universe and the efficient development of commercial telecommunications.
The outer space environment is being degraded by the proliferation of orbiting debris that can damage or destroy manned and unmanned satellites, and already interferes with ground-based astronomy. A scientist at the symposium reported that there is an estimated 2,000 tons of material in low Earth orbit and that the Earth currently is circled by more than 100,000 objects larger than 1 centimeter.
Large, bright objects in space could have ruinous effects on astronomy
as well as on the natural nighttime environment and the cultural values
of people around the world. There are proposals for mirrors to direct sunlight
toward Earth, "artistic"
or celebratory objects in space such as a "star of tolerance" satellite, and advertisements in orbit. Some of these objects would be so bright that they would permanently damage the eyesight of anyone who might look at them with binoculars, according to a report presented to the symposium.
"Astronomy is a vigorous science that continues to rivet the attention of millions of people worldwide. It has given us many important contributions and a sense of our place in a vast and exciting universe. The night sky is an integral part of the cultural heritage of peoples around the world," said Dr. Woodruff Sullivan, of the University of Washington, one of the symposium organizers.
"We cannot afford to allow the pollution of the sky - both by light and radio waves - to deprive us of the ability to unravel the mysteries of the universe. The IAU Symposium called for global efforts to resolve pollution problems that already have deprived millions of their view of the universe, and threaten cultural resources as well as vital research efforts around the world," Dr. David Crawford, Executive Director of the International Dark-Sky Association, another symposium organizer, said.
Future projects that may degrade the space environment at any wavelength of the electromagnetic spectrum should be subject to prior international environmental impact assessment before approval, as is now done for major projects on Earth, the symposium participants recommended.
Dave Finley, National Radio Astronomy Observatory, Socorro, NM USA
FAX: (505) 835-7027
Jacqueline Mitton, Royal Astronomical Society, UK
+44 (0) 1223 564914
FAX: +44 (0) 1223 572892