The actual mission might still be several years away, but Canada’s proposed space telescope could have a major impact on the next wave of astronomical research.
Patrick Côté, principal research officer, National Research Council-Herzberg, the featured guest speaker for Nanaimo Astronomy Society’s May meeting, will talk about the Canadian Space Agency’s mission concept for the Cosmological Advanced Survey Telescope for Optical and ultraviolet Research.
CASTOR is a proposed space telescope that, once launched, will spend about five years photographing the cosmos at light wavelengths that can’t be viewed with land-based telescopes because of the Earth’s atmosphere. Côté is one of a core team of people who have been developing the project for the past 10 years.
“It does the [ultraviolet] and also the blue-green optical region,” Côté said. “So basically it’s a different kind of mission.”
In the next decade, large space and land-based telescope projects in the U.S., Chile and Europe will begin surveying the sky at optical and infrared wavelengths, but CASTOR’s niche is that from space it can focus on the UV, blue and green end of the light spectrum and produce wide-field images at extremely high resolution.
“It’s like Hubble, in that it’s above the atmosphere, so it has very, very sharp images,” Côté said. “So that’s an advantage against the ground-based telescopes because you don’t have the atmosphere to deal with … and it gives you these very sharp Hubble-like image qualities, but it does it over a field that’s 100 times bigger than Hubble.”
Côté said among things new telescopes that can see red and infrared will try to measure is dark energy, but to get a full picture, astronomers also need to study the ultraviolet end of the spectrum.
“You look at the shapes of galaxies and you understand how structures have built up over time since the Big Bang, but to actually interpret that you need to know the distances to individual galaxies … so what you do is you use the images to deduce something about those distances,” he said. “You estimate the distances from how much light they emit in different slices of the spectrum.”
When CASTOR is launched, possibly in 2026, it will likely be designed as a five-year mission. Satellites can be designed to last decades, but the costs are higher. Shorter-life designs can mean lower manufacturing costs. Five years is a compromise between cost versus scientific impact, Côté said, and a costing study is underway.
“This is a fun project,” Côté said. “It fills sort of an interesting niche and it’s something a little bigger than Canada has done in space astronomy in the past, but certainly in our reach.”
Nanaimo Astronomy Society’s May meeting, open to the public, happens Thursday, May 23, 7-9 p.m. at the Beban Park social centre.
To learn more, visit www.nanaimoastronomy.com/.