A Canadian deep-space instrument just found water on a distant planet.
The puffy gas giant, WASP-96b, was captured in unprecedented detail in infrared or heat-seeking wavelengths – and the James Webb Space Telescope is just getting started, along with its Canadian spectrometer.
The international telescopic collaboration launched Webb to space on December 25. The massive telescope then needed to fly 1.5 million kilometres from Earth and undergo a rigorous commissioning period that required dozens of steps and images released so far.
But the big reveal July 12 was an incredible moment in Canadian astronomy. Canada, through the Canadian Space Agency and Honeywell, contributed a spectrometer and Fine Guidance Sensor (pointing device) providing a guaranteed share of telescope time for scientists working in the country.
That’s a huge deal. Webb is going to be the premiere observatory of the next 20 years, if current estimates hold, and Canada’s exoplanet science will take a forward step. The principal investigator of the Near-Infrared Imager and Slitless Spectrograph is René Doyon, an exoplanet instrument specialist at the University of Montreal who has practiced his craft on several ground telescopes.
Doyon thinks what we could be looking at is a “water world,” glowing in the spectrometer at a distance of 1,150 light-years.
“One thing that is predicted to exist are water world planets that have a rocky core with thick oceans around them,” Doyon told reporters during a livestreamed press conference on June 12. He urged more follow-up observations by Webb and other telescopes to be sure, but said Webb’s ability to see water molecules or “water features” is a promising start.
The Canadian spectrometer will be a giant leap over the much older instruments on the Hubble Space Telescope, which can detect exoplanet atmospheres at lower resolution (and from Earth orbit, where stray light can interfere with observations.) Hubble’s first confirmed detection of water in an exoplanet was in 2013.
WASP-96b likely isn’t habitable to life as we know it, but the detection is still a big deal. Yes, the Jupiter-sized planet has searing cloud temperatures of nearly 550 degrees Celsius, and also yes, it does orbit its parent star at an uncomfortably close distance — a ninth of Mercury’s orbit to our own Sun.
But as the planet whips around its star every 3.5 days, Webb demonstrated that its Canadian spectrometer can pick out the delicate signature of a planet’s atmosphere against the intense light of a star. The brightness change the spectrometer detected was only between 0.6 and 2.8 microns, which NASA said was incredibly precise.
NASA said in a statement that it was not only the water that attracted investigators’ interest, but clouds, which were not “thought to exist based on prior observations.” Canada’s NIRISS even picked up oxygen, methane and carbon dioxide, which is huge, as Webb will be tasked to look at those life-friendly molecules in worlds that might be habitable.
There’s already a lineup of observations planned under Webb’s Cycle 1, which will include exoplanet observations of rocky planets that are much closer in size and make up to our own planet. Webb will spend roughly a quarter of its booked time looking at atmospheres and where possible, minerals — meaning, the actual surface of other worlds.
NASA had high praise for the Canadian instrument. “This NIRISS observation demonstrates that Webb has the power to characterize the atmospheres of exoplanets — including those of potentially habitable planets — in exquisite detail.”
Doyon said the spectrometer is ready for work. “There’s many, many new discoveries that we can expect,” he said.
This biweekly column by Canadian science and space journalist Elizabeth Howell focuses on a trending news topic in Canadian astronomy and space.
