Promises kept. The year 2022 will have been marked by the intense activity of a scientific instrument expected for more than thirty years, the James-Webb space telescope, developed by NASA and the European and Canadian space agencies. With a budget of 10 billion euros, launched at Christmas 2021, it has positioned itself more than 1.5 million kilometers from Earth to deploy its gigantic mirror 6.5 meters in diameter and collect precious grains of light. The latter come as well from very distant galaxies, from solar systems in formation, from exoplanets, as from the planets of our Solar System, even from asteroids.
On July 12, the whole world discovered the first five images, like fireworks, chosen to impress and show the exceptional performance of the telescope. First there is a swarm of very old galaxies, only a few hundred million years following the Big Bang. Then that, evoking a magnificent colorful painting, of the Carina Nebula, a mass of dust which stands out once morest a deep blue sky. Less spectacular, but which excites specialists, is an analysis of the atmosphere of an exoplanet. Then, a titanic clash of galaxies, one of which seems to be smiling, Stephan’s Quintet. Finally, a remnant of a star explosion, the Southern Ring Nebula, which forms like a gigantic bubble in the cosmos.
expert eyes
These shots reassure on the operation of the instrument and on its promising future. The telescope does not see in the visible, but in the infrared, which allows it to observe galaxies that are moving away from us, and therefore very far. This wavelength also passes through dust clouds and then reveals hidden details to the eyes of, for example, another iconic space telescope, Hubble. Its ability to also break down the light received into its various wavelengths allows researchers to analyze the composition of the atmospheres or the immense structures bathing the galaxies in order to understand the birth of stars and planets.
Everything is working as well as expected. With the exception, however, of one of the spectrometers, MIRI (which breaks down the light), non-functional for several months. It has not been repaired, as any intervention is impossible at such distances, but the engineers have found a way to use it which avoids the friction responsible for the unavailability.
So, since July 12, spectacular shots have multiplied, arousing justified enthusiasm, even if often the objects taken from life were already well known and spectacular, such as the famous Pillars of Creation. Only expert eyes might be sensitive to new details. Unquestionably, James-Webb has already renewed the public’s gaze on the sky.
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