SETI NEWS Radio astronomy


Larry Klaes (lklaes@bbn.com)
Mon, 28 Jun 1999 15:42:44 -0400


>Date: Sun, 27 Jun 1999 17:02:39 -0400 >From: JAY RESPLER <jrespler@superlink.net> >Organization: SkyViews Astronomy & Space information Web Site >X-Mailer: Mozilla 4.04 [en] (Win95; I) >To: jrespler@superlink.net >Subject: NEWS Radio astronomy > >June 27, 1999 > > > From World's Radio Astronomers, a Simple Plea: > Shhh! > > > Forum > Join a Discussion on Science in the News > > > By MARLISE SIMONS > > ARIS -- Scientists studying the heavens have long been bothered by the > more mundane activities of other earthlings. They have fled to remote > mountaintops to escape the light of the cities. They have adjusted their > radio instruments to cope with the growing avalanche of television towers, cell > phones, pagers, microwave ovens, garage-door openers and the many other > ground-based gadgets that emit radio waves. > > But radio astronomers around the world say they cannot escape the overhead > "pollution" beamed down nonstop from the growing fleet of communications > satellites. > > At observatories like Nancay Radioastronomy Station in France and the famed > Jodrell Bank in England, where pulsars were discovered, astronomers complain > that the enormously powerful signals emitted by the low-orbit satellites are > drowning out the faint whispers coming from the universe. And these manmade > constellations, they complain, are increasingly invading the frequencies assigned > to radio astronomy. > > The satellites are a boon to communications companies and customers, allowing > people to make calls from mobile telephones, send faxes or transmit data from > anywhere in the world. A fleet of 66 such American satellites went into full > operation late last year. More will be launched by Europeans this year to provide > high-speed Internet linkups and many others are planned. > > To radio astronomers, all satellite systems are a nuisance, but they say that the > fast moving communications satellites, whizzing around at just 420 miles above the > earth and blanketing the planet with their coverage, are threatening the survival of > their field. > > At a meeting in Paris this week, science ministers discussed the creation of "radio > quiet zones" where radio astronomers could work. The new zones of several > hundred square miles would be like protected "parks" in different parts of the > world where satellite emissions or other broadcasts would be restricted or banned > at fixed times. > > Such quiet zones would be designated in remote parts of the world with few > customers so that satellite operators could turn off their emissions and radio > astronomers could set up their instruments there. > > "Radio telescopes are extremely sensitive and search for the most subtle radio > signals," said Michael Michalowski, a physicist who attended the meeting. > "What's going on now is like a neighbor turning on a boom box while you are > listening for the sound of an insect." > > Among suitable candidates, which according to satellite records, are still > reasonably "radio quiet," are regions of Australia, China and South Africa. Harvey > Butcher, director of the Netherlands Foundation for Research in Astronomy, said > it was vital to restrict radio signals in these areas. > > China, which has plenty of open land, has already shown some interest in having > such a facility as part of its efforts to improve its science activities, said > Michalowski, who is secretary of the Global Science Forum of the industrialized > nations. Australia, which is both active in radio astronomy and has the open land, > might also participate. > > "It would probably require an international treaty to keep the satellites quiet or get > them to switch off," Michalowski said. > > But some scientists believe that, inevitably, the only place where astronomical > antennas can be free of interference would be the far side of the moon. > > The science ministers from the 29-nation Organization for Economic Cooperation > and Development, meeting in Paris this week, set up a task force to draw up stricter > rules for co-existence between radio astronomy and the telecommunications > industry. Astronomers in Europe and North America have long begged for > government help because they have little clout with the powerful communications > conglomerates. > > The task force will bring together not only astronomers and satellite operators but > also government agencies that invest in astronomy as well as the International > Telecommunications Union, the U.N. body that carves up the radio spectrum. > > Aside from studying the feasibility of creating "quiet zones," the group will look at > other options. One is changing regulations for radio frequency bands, a complex > process that might take at least a decade. Another is to persuade operators to > make future satellites less invasive. > > "We must insure a dialogue of all the stakeholders," said Dr. Neal Lane, the White > House adviser on science who attended the meeting. "We're confident we can > reach an accommodation if everybody gave a little bit." > > Some agreements already exist. Motorola Inc., which operates the 66 satellites of > the new Iridium system that relay phone and paging calls around the globe, has > worked out accords for "quiet time" with American and European observatories. > Iridium will reduce its signals and cut back its interference during certain hours at > night. The agreements took nearly five years of often difficult negotiations and > pressure from European governments, which withheld Iridium's operating > licenses. > > "We are now trying to stay below power levels during nonpeak hours, usually > from 10 p.m. to 6 a.m." said Robert Edwards, a spokesman for Motorola. "Radio > astronomers are in a band close to ours, but we believe we can co-exist." > Astronomers see the agreements as a partial victory, but say that there is not > enough time-sharing and that they will fight to obtain legal limits on interference. > > Above all, radio astronomers fear problems ahead. They are designing > increasingly sensitive instruments to map stars and galaxies as part of their quest > to fathom the origin and the fate of the universe. For example, the Very Large > Baseline Array includes dish antennas extending from the Pacific Ocean to the > Caribbean Sea, allowing astronomers to observe extremely fine detail. > > One project under discussion is the so-called Square Kilometer Radio Telescope, > which would enable scientists to observe the birth of galaxies. It would involve > placing dishes over hundreds of miles. > > Astronomers at the Westerbork Observatory in the Netherlands said this project > would be 100 times more sensitive than current instruments and far more > susceptible to human interference. Eight institutes from six countries are already > collaborating on the design. It is this project that prompted the study to create > protected "quiet zones." > > As for the new task force set up this week, Lane said, "the dialogue will be > spirited." > > "We're building more and more sensitive instruments for astronomers," he said, > "and maybe all we'll hear is your and my family talking to each other." > > > > > > Home | Site Index | Site Search | Forums | Archives | Marketplace > > Quick News | Page One Plus | International | National/N.Y. | Business | Technology | Science | Sports | Weather | > Editorial | Op-Ed | Arts | Automobiles | Books | Diversions | Job Market | Real Estate | Travel > > Help/Feedback | Classifieds | Services | New York Today > > Copyright 1999 The New York Times Company > > > > > >-- >Jay Respler >-- > JRespler@superlink.net >Sky Views: http://mars.superlink.net/jrespler/skyviews.htm > Satellite Tracker * Early Typewriter Collector > Freehold, New Jersey >



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