Wednesday, December 23, 2009

Silent Skies for Radio Astronomers

With the ever-increasing expansion of radio-frequency mobile telecommunication chatter via cellular / mobile phones and other wireless devices, will our skies be “silent” enough for radio astronomy?

By: Ringo Bones

The International Astronomical Union and the International Dark Skies Association had made significant progress recently in stamping out the scourge of urban light pollution during the celebration of the UN sponsored 2009 International Year of Astronomy. Especially when the Galloway Forest Park in Scotland was established as a protected dark sky area for stargazers and amateur astronomers. Unfortunately, nothing has been done for radio astronomers when it comes to the “trivial” problem of the increasing radio-frequency traffic that denied a chatter-free silent sky condition for astronomers who explore the cosmos in the radio portion of the electromagnetic spectrum. Especially in radio frequencies of interest used in exploring our universe like galactic structure and evolution to signs of “extraterrestrial technology”.

As far back as the 1970s, astronomer Carl Sagan raised concerns over the US Department of Defense’s heavily encrypted DARPA Net “Hotline” operating so close a frequency to the hydroxyl radical radio frequency. In 1995, the Strasbourg-based European Science Foundation issued a warning that the rapid expansion of the mobile communications / mobile phone / cellular phone industry’s excessive “radio-frequency pollution” – a.k.a. RF pollution - was a serious threat to radio astronomers worldwide. Back then, Dr. James Cohen of Britain’s Jodrell Bank observatory decried the ongoing deployment of numerous low-Earth-orbit telecommunications satellites used to serve the mobile / cellular phone industry.

Around that time, Dr. James Cohen stated that even if the sideband emissions from satellite / mobile / cellular telephones were small, they would still devastate radio telescopes equipped with large dishes which are so sensitive they can detect extremely weak and distant RF signals on the sub-nanovolt level. Like urban light pollution plaguing astronomers who work in the optical portion of the electromagnetic spectrum, Dr. Cohen likened the problem to a professional photographer having a light shining into his or her lens every time he or she tried to snap a picture. Dr. Peter Napier of the US National Radio Astronomy Observatory concurred with Dr. Cohen, saying that the problems of excessive RF pollution in the radio spectrum of our skies were severe and getting worse as the years go by. Dr. Napier characterized common telecommunications engineering practices as “inadequate” to prevent severe disruption to radio astronomy.

Due to a lack of a legally binding international treaty designed to protect the world’s radio astronomers against excessive RF frequencies reaching into their astronomical instruments or radio frequency pollution. The International Telecommunications Union (ITU) had assigned a frequency of 1410MHz – previously the sole domain of the US DoD during the height of the Cold War to send heavily encrypted data streams – available for civilian use for satellite / mobile / cellular phone systems. Unfortunately, this radio frequency band is dangerously close to the 1412MHz signature of the hydroxyl radical – a hydrogen / oxygen molecular fragment widely distributed in space and is used by radio astronomers to map our universe.

In the time since the European Science Foundation issued its warning against excessive radio frequency traffic ruining radio astronomy, “celestial traffic” via telecommunications satellites around the Earth had increased tremendously. These now support an ever-growing market of dedicated ISDN modem / broadband modem lines / wi-fi / and mobile / cellular phones – not to mention an “experimental” system intended to prevent auto collisions. Not only do these satellites contribute to the RF frequency pollution that spoils radio astronomy - their highly reflective Teflon-coated antennae can also be a source of light pollution to astronomers working in the optical spectrum. These satellites – like the various Iridium satellites and the 24-satellite Global Positioning System in geosynchronous orbits - are probably the only “stars” visible in urban areas plagued by sodium-vapor street-lamp light pollution.

The radio frequency pollution problem shows no sign of abating. Mike Cousins, who runs the Stanford Research Institute’s radio-telescope research program, told the San Francisco Examiner that the problem is “constant, sometimes severe”. There is now a cellular phone tower just over the hill from Stanford’s 150-foot dish, Cousins told the San Francisco Examiner’s science writer Keay Davidson. “There is nothing we can do about it” Cousins says. The Stanford dish is sensitive enough to pick up radar reflections from ships in the Western Pacific and Citizen’s Band radio transmissions from as far away as Florida. Even Seth Shostak of the SETI Institute in Mountain View, California, characterized the radio frequency pollution problem in radio astronomy as “science versus heavy-duty commerce”. Scientists at Seth Shostak’s institute search for radio frequency signals from extraterrestrial civilizations.

Will the radio frequency pollution problem that plagues radio astronomers like urban light pollution problems plaguing astronomers using optical telescopes ever be solved? Most radio telescopes, like their optical counterparts, stand in once-remote and once-uninhabited locations that are now surrounded by highly urbanized civilization with their inherently light and RF polluting lifestyle. Even the International Dark Skies Association had failed to solve the increasing light pollution problem around Mount Wilson Observatory in Pasadena, California.

Recently, radio astronomers have developed a few techniques for separating the extraterrestrial radio signals of interest from the more mundane RF pollution noise. One is by computer correlation of signals received by two or more dishes spaced hundreds of miles apart. Using this technique, radio astronomers can filter out the transmissions of cellular phone “yakking yuppies” and concentrate on the spectrum of interest. The better – if not the best technique – for radio astronomers to beat radio frequency pollution is to build a radio astronomy dish as far away from the earthbound RF noise as possible – like on the dark side of the Moon. Sadly, this project won’t be getting any US Congressional funding anytime soon after the Bush-Cheney Consortium ran their “Global War on Terror in a malfeasant manner that left the US Government mired in a 12 trillion dollar debt burden. Some gifted scientist now smoking weed in Amsterdam could have built a faster-than-light capable spacecraft that carries a crew of 150 with that kind of money.

Monday, December 21, 2009

Can the International Astronomical Union Stop Urban Light Pollution?

As one of the major goals of the International Year of Astronomy 2009 (IYA 2009), does the International Astronomical Union or IAU hold enough clout to stop the scourge of light pollution?

By: Ringo Bones

As the only international astronomical body that has the power to downgrade Pluto from a bona fide planet to a “dwarf planet” status, the International Astronomical Union could have easily stopped urban light pollution. But as of late, many amateur astronomers have always been wondering why the International Astronomical Union had always been “very meek” when it comes to stamping out the scourge of urban light pollution. The question now is, can the IAU – using its political clout – really has the power to stamp out the scourge of urban light pollution? After all, those sodium-vapor lamps that radiate as much light upwards as well as lit our streets is pretty useless when it comes to stopping a 123-grain Lapua Scenar round travelling at 2,600 feet per second, doesn’t it?

When it comes to achieving the “bottom list” of the International Year of Astronomy 2009’s major goals – i.e. on facilitating the preservation and protection of the world’s cultural and natural heritage of dark skies in places such as urban oases, natural parks and astronomical sites. It did manage to score big points recently when the world’s astronomical community voted Galloway Forest Park in Scotland as one of the best stargazing sites on the planet. Galloway Forest Park was even awarded “dark skies” status and praised for accessibility to the general public. The park’s dark skies status accolade was probably due to the healthy tree cover filtering the distant glow of not-so-distant urban nighttime illumination.

Recently, the International Dark Skies Association had tested the levels of darkness in the Galloway Forest Park using a Sky Quality Meter – a method of darkness measurement that would rate a photographer’s darkroom (with the dim red light on?) a rating of 24, the highest reading possible. Galloway Forest Park got 23 out of 24, while the reading in cities such as Glasgow would be 15 or 16.

Despite of its relatively close proximity to major urban centers, it is a miracle that Galloway Forest Park managed to score very high marks on the Sky Quality Meter. But the park’s proximity to northern England, Central Scotland and Northern Ireland – not to mention the ferry port of Stranraer – allowed Galloway Forest Park to score high on the general public accessibility scale in comparison to some other famed but more remote stargazing sites in Britain. Let’s just hope that billionaire property developer Donald Trump doesn’t buy the park in order to turn it into an extremely well-lit casino and golf course. Noting that the full Moon can’t be seen anymore on a well lit nights of the Las Vegas Strip.

To the benefit of us amateur astronomers who live elsewhere on the planet. The International Astronomical Union should be urging governments around the world to redesign streetlights so that they only illuminate the pavement as opposed to our current ones that does double duty of shining a spotlight on four-engine World War II-era night-bombers flying at 25,000 feet. These overly bright streetlights that scatter their light everywhere can’t even make a 9-mm Parabellum round fall to the ground as soon as it leaves the muzzle of a Beretta 92-F – like those “newfangled” inertial dampening field devices. And lets not forget that they don’t even to do double duty either as a quantum-tunneling wormhole that allows our law enforcement personnel to “ miraculously materialize” at the scene of the crime in less than three seconds as far as I know. These overly-bright sodium-vapor lamps that scatter their lights all over the place – especially upwards – not only ruin amateur astronomer’s view of the night sky, they also produce unnecessary carbon dioxide that leads to global warming.