Going back in time and pushing the limits of knowledge: this is the promise of James Webb, the most powerful telescope ever built. French physicist and writer Christophe Galfardstudent and collaborator of the great astrophysicist Stephen Hawking, testifies in the documentary James Webb, journey to the origins of the Universeaired Thursday 13 October, at 21 hours, in France 5. The scientist gives us his impressions of this incredible tool.
France info : What dazzles you most about James Webb ?
Christophe Galfard : Honestly, almost all the collective imagination we have of space is linked to the imagery given to us by the Hubble telescope. It transformed our view of the Universe. There, with James Webb, we are on the next generation. Thanks to it, we have new images which are of spectacular beauty, and which open up to us sections of our cosmic reality which were hitherto unexplored because they were invisible and undetectable. And that’s pretty insane.
For you who are concerned with popularizing science, James Webb is a necessary tool in your research ?
Ah yes, because the images it allows us to have of the Universe are fabulous and allow me, during conferences, to explain many things. And then from a personal point of view, it’s super satisfying to project yourself into such distant places with so much detail. We even see the dust ejected by black holes in ultra-distant galaxies. It’s crazy, and not just for the general public, but also for scientists. Because before Hubble, no scientist had ever seen this kind of images either. It is truly a gift humanity is giving to itself today by having these splendid images.
Are scientists working on these images ?
No, the data scientists are working on is not the images themselves. They can be used, but the raw data has a much more encrypted form. These are large data tables. The original shots restored by James Webb are illegible, a lot of work is needed to make the images look like those beautiful shots that we can admire today. In addition, originally, the colors, which are called electromagnetic waves, whether or not they are visible to our eyes, arrive from space one by one, they are detected independently of each other. While we, when we look at a photo, we have all the colors that are superimposed at once.
Will scientists be able to design an even more powerful telescope ?
Sure. Here we are again on a telescope that uses light that our eyes cannot see, called infrared light. But there are telescopes that will be able to see beyond infrared and will see other particles and signals capable of traversing space and even earlier times. We are not there yet, but the scientists are already working on the next one, even if they are still in the analysis of what James Webb can bring, because we are only at the beginning of its exploitation.
Do you think James Webb will be able to detect extraterrestrial life ?
James Webb has such sensitivity that he will allow us to analyze, as has never been done, the atmosphere of distant planets. It means that we are starting to have tools that will help us detect molecular signals of things that exist on other planets. Moreover, one of the first five images of James Webb that we discovered this summer was precisely related to the atmosphere. It proves that we can do it, so to answer your question, yes, it is quite possible.