On the occasion of the broadcast of the first images of télescope Webb during the summer of 2022, our assistant director Nathalie Ouellettewho is also the communications scientist for the Webb Telescope in Canada, tells us regarding what this mission means to her and to a generation of young researchers.
Nathalie Ouellette, communications scientist for the Webb Telescope in Canada, visiting Webb at the Northrop Grumman facilities in Redondo Beach, California, in 2019. (Credit: Northrop Grumman)
Birth of an astrophysicist
People often ask me how I became an astrophysicist. Like many of my colleagues, I fell in love with the wonders of the cosmos at a very young age. However, given that I was born and raised in a major urban center, in Montreal, by parents who didn’t really take us camping, I didn’t grow up with starry skies above the head. I’ve been lucky enough to have a few more direct astronomical experiences, like observing Comet Hale Bop in 1997 or spotting Jupiter and its moons in a telescope from our backyard. However, most of my wonder at space came from the images I saw in books at the library and in the TV documentaries my parents, both engineers, encouraged me to watch.
These books and documentaries were filled with incredible images of galaxies, nebulae and planets in our Solar System. I was only 2.5 years old when the Hubble Space Telescope was launched and 6 years old when its first service mission, which corrected flaws in its optical system, took place. I grew up with Hubble, and was just one of millions, if not billions, of people who fell in love with this mission and how it allowed us to see the Universe like never before.
I now know that at that time, behind the scenes, work was already beginning for the next great space observatory. The ” Next Generation Space Telescope “, which would eventually be renamed the “James Webb Space Telescope”, was being developed to take up the torch from Hubble and see further into the Universe than ever before thanks to an unprecedented collaboration between the NASAl’European Space Agency and theCanadian Space Agency.
I’ve only been a member of the Webb team for 4 years, and many of my colleagues have spent the majority, if not all, of their professional lives working on this mission. But I still have to pinch myself at the idea of being part of this incredible adventure whose seed was planted just when my passion for science and space was also taking shape! And, as the Communications Scientist for the Webb Telescope in Canada, it’s my job to make sure that all Canadians feel part of this adventure!
About Webb
An artist’s rendering of the James Webb Space Telescope (Credit: NASA).
Although the Webb telescope is often presented as the successor to Hubble, the two missions are in fact complementary and have important distinctions. Of course, in the spirit of always pushing the boundaries of scientific discovery, the Webb’s mirror has an area regarding 7 times larger than Hubble’s. This makes Webb the largest space telescope ever built, with an 18-segment primary mirror 6.5 meters wide and a sun shield the size of a tennis court.
The Webb is so large that it had to be designed to fold on itself so that it might fit inside the Ariane 5 rocket that launched it into space. Its 14-day deployment to its final destination, the Lagrange 2 point located 1.5 million kilometers from Earth, is undoubtedly one of the most complex technological maneuvers ever carried out by humanity. And, thankfully, it went off without a hitch thanks to the many rigorous tests Webb underwent while still on Earth!
Another key difference between Webb and Hubble is the type of light they observe. The Hubble telescope is sensitive to the same light as human eyes: visible light. He can also see a little in the ultraviolet and very near infrared. The Webb, on the other hand, was designed to observe infrared light, because one of the original scientific purposes of the Webb telescope was to observe the first galaxies that formed following the Big Bang. This light comes to us mainly in the infrared, because the light, first emitted in the blue and ultraviolet, is stretched to longer wavelengths due to the expansion of the Universe.
Luckily, there are also a multitude of fascinating celestial objects such as planets (inside and beyond our Solar System), cool stars and protoplanetary discs that glow in the infrared. Another benefit of infrared observation is its interaction with cosmic dust and gas that are scattered throughout much of the cosmos. Near-infrared light can pierce this dust (while visible light is blocked by it), unlocking the secret to hidden processes like star birth. Dusts and gases themselves shine in the mid-infrared.
The first six months of Webb’s mission, starting with its incredibly successful launch from French Guiana on December 25, 2021, have gone better than the team might have hoped. This commissioning phase was an incredible display of teamwork, scientific rigor and amazing engineering feats that included alignment of the Webb mirror, cooling of the observatory, as well as calibration and the testing of all his instruments.
Webb’s first images
Image of the star forming region NGC 3324 in the Carina Nebula, observed by the NIRCam and MIRI instruments of the Webb telescope. (Credit: NASA/ESA/CSA/STScI)
After six long months of commissioning the Webb Telescope, the world was rewarded for its patience on July 12, 2022, when the first full-color, high-resolution images of the mission were unveiled. The five published r/sults, four photometric images and a spectrum, were accompanied by numerous additional infographics and images. The objective of this first publication was to show the potential of all of Webb’s instruments in their different modes of use, observing a series of different types of objects, from exoplanets to extremely distant galaxies. Another goal was, of course, to arouse the awe and wonder of all who saw these images. I sincerely believe that the publication was a huge success on both fronts!
Among the images revealed include the first Webb Deep Field (more than 7000 galaxies, some appearing as they were 13.1 billion years ago), the carina nebula (an incredible landscape of cosmic cliffs showing the birth of stars), the austral ring nebula (a planetary nebula resulting from the death of a star) and the stephan quintet (a group of interacting galaxies).
A graph showing the atmospheric transmission spectrum of exoplanet WASP-96b, as collected by Canada’s NIRISS instrument on the Webb Telescope. The bumps and ripples in the spectrum indicate a clear detection of water vapor in the exoplanet’s atmosphere. (Credit: NASA/ESA/CSA/STScI)
I must give special mention to the atmospheric transmission spectrum of exoplanet WASP-96 ba hot gas giant planet located 1150 light years away, taken by NIRISS, the Canadian instrument aboard Webb. This incredible data set demonstrated the mind-boggling power, resolution and sensitivity of NIRISS in determining the atmospheric composition of distant exoplanets. In the case of WASP-96 b, we saw definite detection of water vapor and strong evidence of the presence of haze and clouds.
Although not a scientific instrument, the fine guide detector (FGS) from Webb allows the telescope to acquire all of its celestial targets during each of its observations and produce the high-quality images we see. The FGS, which is Canada’s other contribution to the mission in addition to the NIRISS instrument, is therefore a mission critical element of which we can be proud.
The next steps
Of course, the first images of Webb are really only the beginning of the mission. The images published represent only 5 days of observation of the telescope! With an estimated lifespan of 20 years, I can assure you that Webb will enable countless scientific discoveries that will revolutionize the world of astronomy and our understanding of our place in the Universe. The first year of observations has already been scheduled, and that includes many programs led by Canadian astronomers. But at the end of the day, we want everyone to make this telescope their own. Because Webb and other space astronomy missions like this are meant to nurture our curiosity and wonder at the mysteries of the Universe. And the Universe belongs to all of us.
First images of Webb
View and download the first images of Webb on the STScI website
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