Once again, NASA is demonstrating its ability to communicate. It was Joe Biden himself, in the presence of the head of the US space agency, who on the night of Monday the 12th unveiled the first scientific snapshot taken by the James Webb Space Telescope (JWST). ” We both wanted an interesting picture, representative of the mission’s scientific goals, and which evokes a wow effect among the general public. ”Explained in early June Klaus Pontoppidan, one of the astronomers working on the mission.
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A successful bet with this photo of the galaxy cluster SMACS 0723, which, acting as a magnifying glass, also made it possible to reveal very distant cosmic objects located behind, an effect called gravitational lenses. The captured galaxies, which are thousands in the picture, are very old when they were formed shortly after the Big Bang more than 13 billion years ago. This image, the deepest so far of the distant universe, was produced on July 11, 2022. Others are to be unveiled on Tuesday.
The telescope was launched last Christmas and underwent six months of testing and experimentation after being deployed in space. The time to install all the elements, to check that the scientific instruments are working properly and above all to adjust the main mirror, which is responsible for collecting the light of the universe.
Once the telescope is pointed in the right direction, this light and many other data are collected and then reprocessed. Because if science needs raw information, the general public prefers beautiful photos to incomprehensible paintings. ” The reprocessing of an image can take a few hours or a few weeks depending on the complexity and the desired result. “, Describes Alyssa Pagan, a scientific illustrator at NASA, who worked in particular on the images of the Hubble Space Telescope. The images are recalibrated first, then colored.
No question of putting any color: the shortest wavelengths received are in the shades of blue, the longest in the reds and the interval between the two in a palette of green. ” For brightness and contrast, we try to bring out the interesting details without saturating the brightest stars.continues the specialist. All in all, as long as scientific information is preserved, we have real artistic freedom, just like photographers. By comparing with her colleague, Joseph DePasquale, she does not always achieve the same result from the same image.
266 scientific projects accepted
For the future, the use of the telescope will be shared between different projects. The teams and agencies that participated in its construction and implementation will, of course, benefit from observation time. Europe is thus insured for at least 15% of the JWST period. For scientists who did not participate in the development of the mission, calls for projects have been launched.
More than a thousand applications were received for the first year of use, and 266 were accepted by the International Selection Committee, consisting of astronomers and engineers. For example, let us cite one project to observe the growth disks around black holes, another to decipher Pluto’s climatic system, or another to study the atmosphere on the exoplanet Gl 486 b.
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The James Webb Telescope should work for at least 10 years. Astronomers are actually betting on a longer duration, especially thanks to the perfect launch of Ariane 5, which has saved fuel. This fuel reserve will keep the observatory in place in space, 1.5 million kilometers above our heads.