After unveiling the first image of the James Webb Space Telescope, NASA released during a conference, drop by drop and with explanations, several other images of the Hubble replacement provided by the European Space Agency and NASA. Hervé Doll, an astrophysicist and professor at the University of Paris-Saclay, is very satisfied and excited by these new images and the scientific perspectives they open, while remembering that they are the culmination of A human adventure for more than thirty years.
>> In the pictures. Space: Here are all the first images of the James Webb Telescope
franceinfo: NASA has just released other images captured today by the James Webb Telescope. big moment for you?
Herve Doll: abnormal. We have been waiting for this for decades and even if we somehow participate in this collective adventure, we are still amazed at the quality of the images and signals that come from the depths of the universe. Inevitably, we’ve been building this en masse for years so we knew what to expect. But it’s still always better to see that what we’ve planned work, including the unexpected things that allow us to see new galaxies. We have little red dots that we haven’t seen before and some of them have been confirmed by the famous infrared spectrograph, particularly a very distant galaxy. In fact, the spectrum may be like a PCR test compared to the thermometer you do when you have Covid. Pictures are a bit like a thermometer: they give you a very good initial diagnosis, certainly very useful, but if you do the test with a spectrogram, there is a lot of information. So it’s less attractive than the pictures, but in terms of information, it’s brutal.
There are many scientific developments we imagine now in your hands with data to study…
Yes, it is a scientific success that began: in one week, all these results are already obtained and 20 years of James Webb operations are expected. There is technical and technological success because the technologies that were used on board were mostly transferred for the first time. And it works perfectly: there were more than 300 failure points that could prevent everything, and everything worked perfectly. And then, it’s a human adventure: there are people who have been working on it for over 30 years, and some colleagues are actually retired at times.
“It really is a great human adventure.”Hervey Doll, astrophysicist
Some of the images that reach us from a distance of 13.5 billion light-years. It’s hard to understand what you mean…
Basically yeah, it’s almost the first galaxies we try to see, looking in the past. Light has a finite speed, so when you look at the moon, for example, you see it as it was a second ago, because light takes a second to arrive. There, we go a little further: 13.1 billion years in this case. In fact, we saw a distant light representing the cosmic background of the European Planck satellite, but at that time in the universe, just after the Big Bang, there were no galaxies. James Webb will see the first galaxies, so they are not farther, on the other hand, they are the most “formed” in some way.
More on a personal level. Was there a photo that charmed you when you discovered these shots?
This is the first image shown by Joe Biden, Vice President and colleagues from NASA. This image is of a very deep field. Within a few hours of exposure, we had it all. It’s an ugly promise.