A group of Victoria astronomers and engineers is revealing planets light years away more clearly than ever before by using microscopic measurements made in milliseconds.
Their moving mirror is a key component of what will be the world’s largest telescope, to sit high atop Hawaii’s tallest mountain.
When it is completed, the Thirty Meter Telescope, known as TMT, will be three times bigger than any telescope on earth today.
"What makes TMT special is it’s going to incorporate something we call adaptive optics, and that’s what we’re building here in Victoria," said David Andersen, research officer with NRC-Herzberg Astronomy & Astrophysics.
In simple terms, they are creating a mirror which changes shape to compensate for the earth’s atmosphere, which distorts images coming from light years away.
"The atmosphere is turbulent, and that turbulence disturbs the images, it’s behind the children’s song, Twinkle Twinkle Little Star. The stars move around because the atmosphere has pockets of warmer and cooler air and that disturbs the light," said Andersen.
Andersen explained that without adaptive optics, flat light will resemble a warped potato chip.
“It’ll have all these ridges and it’ll be wavy, so it’ll be a crazy potato chip. Our system has these things called wave front sensors to sense the wave front and so it takes a picture that allows us to take measurements of how flat the wave front is."
Those measurements get processed by a super fast computer, then commands are sent to a deformable mirror.
"Eight-hundred times a second we are changing the shape of two mirrors very slightly so that they take out the twinkle of the star and leave you with the sharpest possible image," said Andersen.
(Courtesy TMT International Observatory)
The mirror only has to change shape by 10 microns to create a clearer picture. A micron is one-millionth of a metre.
The system is called the Narrow Field InfraRed Adaptive Optic System. It is known by the acronym NFIRAOS, pronounced "nefarious."
About a dozen engineers and astronomers in Victoria are involved with NFIRAOS, and it has been Andersen’s main focus.
"I came here because this is a real centre for astronomical instrumentation and adaptive optics is something that I’ve really been fascinated by and have grown to become more of an expert in over time," he said.
It is a massive high-tech enterprise already a decade in the making and it could take almost another decade to complete. Construction is expected to begin on a new building in Victoria this summer to house NFIRAOS.
With the help of NFIRAOS, the new telescope will be the most advanced on earth.
"TMT, with its 30-metre (nearly 100-foot) diameter mirror, will have nine times the light gathering capacity of the most powerful current telescopes and, with an adaptive optics system that corrects for the blurring of the atmosphere, it will produce images ten times sharper than the Hubble Space telescope," wrote the TMT International Observatory.
TMT has the potential to increase humans’ understanding of space in astounding ways, by allowing astronomers to explore galaxies, gain a better understanding of phenomena like black holes, and find new planets outside our solar system.
“It’s a very hot topic in astronomy, very important and there are many plans on TMT to build different instruments to look for planets and not just look for planets but try to characterize them and the big thing is to look for biomarkers,” said Andersen. “We’re trying to find life on other planets within 25 years."
(Courtesy TMT International Observatory)
Canada is a partner in the $1.4-billion telescope, along with the U.S., China, India and Japan.
Another Victoria team is working on IRIS, a system which works along with NFIRAOS, and a Vancouver company is building the telescope’s enclosure.
Andersen said he is as excited about working on NFIRAOS today as he was the first time he experienced anything like it.
“It is really cool and the first time I was at a telescope and saw the adaptive optic system work, you go from a big blurry blob to a sharp image of the star, it’s special.”
