
There are some astronomy projects that are better done far away from observatories, or any other form of human activity.
The enormous amount of interference from our power lines, electric motors and most of all, digital devices can totally obliterate the signals being sought. Years ago, an ionospheric physicist friend and I worked on such a project. We wanted to observe the waves launched onto the field lines of the Earth's magnetic field by the rubbing of the solar wind over its outer surface, the magnetopause.
Since the magnetic field lines dive down to the North Magnetic Pole, which lies under the Canadian Arctic, we just needed a quiet, deserted Canadian location for our equipment. We finally selected the Algonquin Provincial Park, in Ontario.
It was a hot, clear, summer's day in Ottawa when we loaded the equipment into the car for a drive of some 250 kilometres. There were two possible routes to the Algonquin Park. One, Ontario's Highway 17, runs just south of the Ottawa River, which is more direct but less scenic, and Quebec's Highway 148, longer, but more scenic and running north of the Ottawa River.
We chose the Quebec option. We crossed back into Ontario at L'Isle aux Allumettes, passed through the town of Pembroke, and continued into the park. Now we were on a dirt road with, thanks to heavy logging traffic, severe washboard surfaces on every hill and bend. There is a major radio observatory and an important power line in the park. We had to avoid both.
After crossing the Barron River Canyon we turned right onto a narrow, dirt road and headed up it for two or three kilometres. It was a strip of dirt with dense forest either side. We found a place where we could pull off the road with a chance of being able to get back onto it, and set up our experiment.
The detector consisted of a very long length of electrical cable with ten cores in it, connected so that when laid on the ground in a loop, some 15 metres across, it formed a ten-turn coil. We threaded it on the ground among the trees, helped by countless black flies. In the car we had a sensitive audio amplifier and a battery powered tape recorder. We had no digital devices because of the interference issue. Screening them would be more work than using an old tape recorder and digitizing things later. By the time we had the stuff up and running it was dark.
The bugs had gone home, so we did not need to swelter in the car as an alternative to being eaten alive. Air conditioning was not an option because running the car would create interference. We listened to the signals as they came in, while recording them.
The rubbing of the solar wind makes waves in the field lines, rather like a bow making waves in a violin string. These waves then travel along the field lines, down to the ground, and some of them passed through our loop, being converted into electrical currents which we amplified and recorded. They sounded like feeding time at an alien cosmic zoo.
There were rising and falling whistles and tweaks, various hissing noises and assorted clicks, and under all of it, the inevitable, although faint hum from distant power lines.
In a completely dark environment, the clear, night sky looks grey. I will never forget the experience of standing by the car, surrounded by the black silhouettes of high trees, with that strip of grey sky, sprinkled with stars, while listening to those sounds from space.
Space is filled with interacting magnetic fields. Imagine what we might pick up if we could put a nice big coil somewhere out beyond the edges of the Solar System, in interstellar space. One day it will happen.
In the meantime, since this is my last column before Christmas, I wish you all a merry Christmas and a happy New Year.
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• After sunset, Venus shines low in the southwest.
• Saturn lies in the south and Jupiter is rising in the northeast. Mars rises about three hours later. • Mercury lies in the southeast just before dawn.
• The Moon will be new on Dec. 30.
This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.