The James Webb Telescope between ingenuity and promise

the James Webb Space Telescope, since the summer to observe the beginnings of the universe and the atmospheres of distant planets, and the year 2022 was marked by exceptional images. Great discoveries await in the coming years. Installed 1.5 million kilometers from Earth, behind the Hubble Space Telescope, itself still in operation, it has been dazzling astronomers with images of unprecedented resolution. Cherry on the cake Its firing accuracy allows for a minimum life of twenty yearsfor a guaranteed minimum of ten.

“It behaves better than expected from every point of view,” explains Massimo Steavelli, mission chief at the Space Telescope Science Institute, which controls the operation of the observatory: “The instruments are more efficient, the optics are more accurate and more stable.” Essential stabilization for sharp images.

Images are usually not visible to the naked eye

The general public also benefits, thanks to the colorization of the telescope’s output, images of which are normally invisible to the naked eye. Unlike Hubble, which observes the universe primarily in the visible spectrum (which is perceived by the human eye), James Webb “sees” in the infrared. A radiance that every object naturally emits, from stars to flowers.

At this wavelength, James Webb could detect the faintest flashes of the distant (and therefore ancient) universe, pierce the veil of dust that hides a star factory in a stellar nebula or even analyze the atmospheres of exoplanets using spectrometers.

process of unprecedented complexity

The device’s first tests of small rocky planets in the habitable zone, potentially similar to LandLisa Kaltenegger, professor of astronomy at American University at Cornell, says:

James Webb’s flight on a rocket Ariadne 5 The end of 2021 is the culmination of a journey that NASA began more than thirty years ago. After several setbacks, ten billion dollars and the work of 10,000 people, the 6.2 ton telescope succeeded in an unprecedentedly complex operation.

He was on his way to his final position when Webb deployed a tennis court-sized sun visor. Tennis, then its main mirror with a diameter of 6.5 meters. Once calibrated to an accuracy of less than a millionth of a meter, the mirror’s eighteen petals began collecting starlight. On July 12, 2022, she presented five avatars of her abilities: a procession of thousands of galaxies, some dating back to a period shortly after the Big Bang, 13.8 billion years ago, and a nursery of stars in the Carina Nebula. .

lately, Jupiter It appeared with a lot of details, which will help to understand the inner workings of this gas giant.

“Excess” galaxies

The audience marvels at shades of blue, Red and gray presented by the image of the Pillars of Creation (huge pillars of dust where stars are born). Scientists see it as a way to “reexamine their models of star formation,” according to NASA. In the fifth month of his observations, astronomers have found the most distant galaxies ever observed, one of which only existed after 350 million years of history. the great explosion. With a surprise: it appears to be much brighter than theory predicted and could have formed earlier than expected.

“We have an excess of galaxies, compared to the models, inbeing Away, ”according to a report by David Elbaz, Scientific Director of the Department of Astrophysics at the French Authority for Alternative Energies and Atomic Energy (CEA). Another surprise, when Hubble saw “mainly galaxies with irregular shapes, James Webb’s resolution makes them appear as wonderful spiral galaxies,” Similar to ours A kind of “universal model”, which is probably one of the keys to the formation of stars.

and “an abundance of small globular clusters”, clusters of a few million stars, which could be “a kind of missing link between the first stars and the first galaxies”.

In the field of exoplanets, we have obtained the first confirmation of the detection of carbon dioxide in the atmosphere of Wasp 39-b, with possible photochemical phenomena in its clouds. These first observations gave Massimo Steavelli hope for “great things, not yet noticed or revealed.”