The James Webb Space Telescope delivers its first images of the Universe

A multitude of luminous points behind which it becomes difficult to see the absolute blackness of the universe. A series of images heralding a promising future. Last Thursday, NASA released the first images taken by the instruments on the James Webb Telescope (JWST), which is about 1.5 million kilometers from Earth.

The space observatory, which launched on December 25 aboard an Ariane 5 rocket, has since experienced no program problems that should lead it to make its first scientific observations this summer. After completing its deployment and reaching its final destination in January, it successfully aligned all 18 segments of its primary mirror in March, providing its first-ever crisp image of the star 2MASS J17554042+6551277, located 2,000 light-years from our planet.

The star 2MASS J17554042 + 6551277, first image taken by the JWST.NASA/STScI

All that remained was to calibrate the four instruments, all of which worked in the infrared range. That meant giving them time to reach their operating temperature – which is around -266°C for one of them, the MIRIM imager. A milestone achieved on April 21, according to NASA, which allowed the mission’s engineers and scientists to steer the JWST toward the Large Magellanic Cloud, a dwarf satellite galaxy of our Milky Way.

“Science will take a giant step forward”

This allowed the instruments to capture and restore the series of images revealed last week by the US space agency, showing hundreds of thousands of stars. “Following an extensive review, it was confirmed that the telescope was capable of capturing sharp and well-focused images,” she wrote in a statement, adding that the telescope’s “optical performance” “exceeds expectations.”

The Large Magellanic Cloud imaged by JWST instruments.

The Large Magellanic Cloud imaged by JWST instruments.NASA/STScI

“That first picture moved me. […] It was great straight away and we could see the image quality we were looking for,” said Pierre-Olivier Lagage, an astrophysicist at the CEA and who helped develop the MIRIM imager, on Twitter. “I am now certain that we will see things that have never been seen before, extraordinary,” he continued. Science will take a great leap forward. »

“These remarkable images show what can be achieved when there is a bold scientific vision to explore the universe,” Lee Feinberg, director of James Webb’s optical elements, was quoted as saying in a NASA statement.

Two more months of patience

There is one very last step before the JWST actually enters active service. The engineers test all the observation modes allowed by the instruments to measure their performance and correct the calibration.

They will also conduct thermal stability tests, which consist of measuring the variation in optical quality and alignment of the infrared systems depending on the position of the telescope and the angle at which solar radiation hits the thermal shield. This phase “will last approximately two months before operations begin in the summer,” NASA says.

The “$10 billion telescope” will therefore be able to attempt to accomplish the mission it was designed for: to capture the light signals emitted by the very first galaxies that formed after the Big Bang 13.5 billion years ago , and perhaps give us answers about the birth of the universe.

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