What do a beekeeper, a college administrator and a diamond mine have in common? They all play pivotal roles in a unique project called THEMIS led by NASA and the Canadian Space Agency, whose goal is to study the mysteries behind the Northern Lights. From coast to coast across Canada, a select group of people from all walks of life are volunteering to maintain digital-imaging cameras in their backyards that diligently scan the skies nightly for auroras.
"This is the first-ever attempt at doing a continent-wide campaign to image the auroras, and our custodians are a critical link in this sophisticated NASA-CSA mission," says Mike Greffen, Canadian THEMIS Project Manager at University of Calgary. "We are so fortunate to have such an engaged bunch of volunteers monitoring and maintaining our ground stations in their communities."
Only two years into this historic project and these observatories, together with five satellites, have already begun to answer one of the most puzzling questions surrounding this eerie space phenomenon: what sparks these cosmic fireworks?
Auroras occur when charged particles are thrown off the Sun as solar wind, which then travel across interplanetary space, eventually interacting with the Earth's magnetic field. This then sets off the seemingly random, colourful bursts in auroras, known as substorms, which the THEMIS mission is trying to understand. During auroral activity, as the THEMIS satellites measure dynamic processes happening in near-Earth space, a fleet of observatories across Canada looks up, creating a simultaneous mosaic of the night sky while capturing any substorm activity. Substorms have puzzled researchers for decades. Previous studies have not been able to pinpoint where the energy of the solar wind erupts into these dynamic displays of auroras.
To track down the answer, the THEMIS team at the University of Calgary are operating a network of 16 ground-based observatories across Canada's North in communities like Whitehorse, Yellowknife, Inuvik, Athabaska, Chibougamou and Goose Bay. At the heart of each station is an automated digital all–sky camera with a 360° field-of-view lens that looks straight up, protected under a dome. When darkness falls, the cameras take images of the entire sky every 3 seconds until dawn. These images are stored on an external hard drive which, Greffen explains, is swapped out by the custodian about every 4 months or so with the old one sent back to the researchers in a prepaid pelican case through the mail. "This is really mission-critical because we only get back low-resolution versions of the data through the internet, but the full-resolution, digital version comes back by good old Canada Post."
Not surprisingly, the THEMIS team is wading through enormous amounts of data: they collect about a gigabyte of data per night—per site. By last count, the data set is a whopping 16 Terabytes for 2 to 4 years of operation. The observatories are scheduled to continue operation well into 2011.
The brains behind the camera system is a computer that is in charge of housekeeping, taking into account power failures, and extreme temperatures. A battery backup, heater and air conditioner keeps everything functioning 24/7. A hi-speed internet connection using a satellite modem monitors equipment health and transmits low-resolution data back to the University of Calgary. A GPS unit controls each imager to ensure that all observatory across Canada snaps pictures at the same time, which is important to compliment the THEMIS satellite data.
Greffen explains that each station is simplistic by design, with a lot of off-the-shelf technology, but is can run efficiently in remote locales under extreme environmental conditions. It hasn't been easy to find the right sites for the observatories in remote locations. The observatories have to be far away from light pollution, while ensuring access to the necessary electrical power to run the equipment. "We have had to make some compromises simply because up north where it's dark for 6 months a year, where they have power, they put on lights," explains Greffen.
There are challenges for custodians, too. Clint Sawicki, Manager of the Northern Research Institute of Yukon College in Whitehorse, has a lot of trees surrounding the observatory on his property. So Greffen and his team placed Sawicki's camera on top of a 30-foot electrical power pole. Sawicki says it can be a real challenge to clean the dome during minus 35-degree winters. Occasionally, local wildlife take interest in the observatories' domes. Custodians in Pinawa, Manitoba, who are also beekeepers, need to make sure the insects stay away from the installation. In Fort Smith, Northwest Territories, ravens have come to enjoy standing on the heated dome to keep their feet warm in 40-below winters. Not surprisingly, the ends up getting scratched. But Greffen has since found a solution for salvaging the domes: "while servicing the Gillam observatory [which is on the roof of a helicopter hanger], I saw these bottles of polish in the hanger and asked the pilots about it. I had just come from the The Pas where the dome had been so badly scratched that I had to replace it. I tried this polish on the 'ruined' dome and was amazed. We now have bottles at every site."
For most (if not all) custodians like Sawicki, it really is a labour of love and the excitement that they are helping to push the forefront of science. "We have always been infatuated with the Northern Lights, and just to have the opportunity to see what researchers can do with this data is amazing. What they already found out with all the images is pretty mind-boggling."
Sawicki believes these magical dancing lights in the sky are simply part of the north and part of their life. "While people travel here from around the world to see the Northern Lights, for us its part of our culture, our town and we are just lucky enough to see them regularly," says Sawicki. "The THEMIS project images for me just brings it all together."
The THEMIS science team is led by the University of California at Berkeley on behalf of NASA, and brings together scientists from the US, Canada and Europe. The Canadian THEMIS team is funded by the CSA and includes the universities of Calgary, Alberta, New Brunswick, Saskatchewan and Athabaska University; and Natural Resources Canada.