James Webb Space Telescope captures crisp views of invisible light

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The James Webb Space Telescope has the sharpest perspective on otherwise invisible light in the universe.

The long-awaited first science images from the world’s first space observatory aren’t expected until this summer. But recent test images captured by the telescope during its final phase of commissioning give a glimpse of what lies ahead.

“These are the sharpest infrared images ever taken by a space telescope,” Michael McElwain, Webb Observatory Project Scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said at a press conference on Monday. .

Webb will be able to peer into the interiors of exoplanet atmospheres and observe some of the earliest galaxies created after the universe began by viewing them through infrared light, which is invisible to the human eye. The images were taken after the telescope’s massive golden mirror segments were successfully aligned. The test images show the clear, well-focused images that the observatory’s four instruments are capable of capturing.

But the most striking result came from a comparison of images taken of the same target by Webb’s mid-infrared instrument with the now-retired Spitzer Space Telescope’s infrared array camera.

Spitzer, once one of NASA’s Great Observatories space telescopes, was the first to capture high-resolution near- and mid-infrared images of the universe.

Webb’s giant mirror and sensitive detectors can pick up even more detail – and enable more discovery – than Spitzer.

Scientists studying the two images of the Large Magellanic Cloud, a small neighboring galaxy to the larger Milky Way, noted that Webb’s image reveals unprecedented detail about the interstellar gas between stars.

“You can understand that Webb’s images are going to be better because we have 18 segments, each of which is larger than the single segment, so to speak, that formed the mirror of the Spitzer telescope,” said principal investigator Marcia Rieke. for Webb’s near-infrared camera and professor of astronomy at the University of Arizona, during the press conference.

“But it’s only when you actually see the kind of image he provides that you really internalize and say to yourself, ‘Wow, just think about what we’re going to learn.’ Spitzer taught us a lot. It’s like a whole new world.

Webb is now in the final stages of preparation before it is ready to begin making scientific observations.

“I would call it the home stretch,” McElwain said. “We have planned about 1,000 activities for go-live, and only about 200 activities remain to be completed.”

Webb’s instruments undergo their final checks and calibrations as the telescope team on the ground evaluates the performance of each to ensure they are ready to collect data correctly.

Each instrument has about four or five science modes, each of which must meet specific criteria. One of Webb’s special modes includes tracking moving targets, which is especially useful for scientists who want to study objects on the icy expanses of our solar system as they orbit the sun.

“When this phase is complete, we will be ready to unleash scientific instruments on the universe,” McElwain said.

Webb’s first images of the universe, called early release observations, or EROs, are expected to come out in mid-July, Klaus Pontoppidan, Webb project scientist at the Space Telescope Science Institute in Baltimore, said at the press conference. . A more specific date will be shared later, he said.

These first “spectacular color images” will show Webb fully operational and celebrating “the beginning of many years of science,” Pontoppidan said.

Webb’s exact targets for these early images have not been revealed as the telescope team doesn’t want to spoil the surprise. And those goals could change as the team gets closer to capturing images.

The first images will look like what we are used to seeing Hubble Space Telescope in terms of aesthetic quality, Pontoppidan said.

“Astronomy won’t be the same once we see what (Webb) can do with these early observations,” Christopher Evans, Webb project scientist at the European Space Agency, said at the press conference.


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