After unveiling the first image of the James Webb Space Telescope, NASA published during a conference, drop by drop and with explanations, many other pictures of the Hubble replacement made by ESA and NASA. Hervé Dole, astrophysicist and professor at Paris Saclay University is very satisfied and excited by these new images and the scientific perspectives they open up, while recalling that it is the culmination of a “human adventure of more than thirty years.”
>> IN PICTURES. Space: here are all the first images of the James Webb telescope
franceinfo: NASA has just published other images captured today by the James Webb telescope. A big moment for you?
Herve Dole: Extraordinary. We’ve been waiting for this for decades and even if we participate in one way or another in this collective adventure, we’re still amazed by the quality of the images and the signal that come from the depths of the universe. Inevitably, we have designed this collectively for years so we knew what to expect. But it’s still always better to see that what we have planned works, and including unexpected things that allow us to see new galaxies. We have little red dots that we had never seen and some of which have been confirmed by this famous infrared spectrum, in particular a galaxy very, very far away. In fact, the spectrum could be a bit like a PCR test compared to a thermometer that you do when you have Covid. The images are a bit like a thermometer: it gives you a very good first diagnosis, certainly very informative, but if you do the test with the spectrum, there you have a lot more information. So it’s a little less sexy than the pictures, but in terms of information it’s just monstrous.
There are many scientific advances that we now imagine in your hands with data to study…
Yes, it is a scientific success that is beginning: in one week, all these results have already been obtained and twenty years of James Webb operations are expected. There is technical and technological success because the technologies that have been onboard have mostly flown for the first time. And it works perfectly: there were more than 300 failure points that could block everything, and everything worked perfectly. And then, it’s a human adventure: there are people who have been working on it for more than 30 years, some colleagues are sometimes already retired.
“It really is a major human adventure.”Hervé Dole, astrophysicist
Some images that come to us from 13.5 billion light years away. It’s even hard to realize what it means…
Yes basically, it’s almost the first galaxies that we try to see, we look 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 an even more distant light which is the cosmic background with the European Planck satellite, but at that time in the universe, just after the Big Bang, there were no galaxies. James Webb is going to see the first galaxies, so it’s not what’s further away, on the other hand it’s what’s most “formed”, in a way.
More personally. Is there an image that fascinated you when you discovered these shots?
This is the first image shown by Joe Biden, the vice president and colleagues from NASA. This image of a very deep field. In a few hours of exposure, we have all that. It’s a monstrous promise.