These images, which promise to be spectacular, are awaited by researchers around the world and will have to demonstrate the immense capacities of James Webb.

The exact date of the publication of this real surprise package will be specified later, and its content kept secret until the last moment.

Images taken by the four onboard science instruments will be released, promised Klaus Pontoppidan, James Webb's science program manager at the Space Telescope Science Institute, which operates the telescope from Baltimore.

Another indication: "all themes" of scientific observations of the telescope will be represented, he said at a press conference.

Namely: the very young universe, the life cycle of stars, or even exoplanets...

The telescope operates in the infrared, and will therefore observe "colors not in the visible spectrum" for the eye, detailed Mr. Pontoppidan.

Before publication, it will thus be necessary to "translate the infrared colors into visible colors, which humans can see."

At the end of April, James Webb had completed the alignment phase between its huge main mirror and its four scientific instruments.

Images taken by the telescope have already been published, but these were vast star fields, used to calibrate the instruments, and not astrophysical targets of scientific interest.

For the images that will be revealed in mid-July, a committee has been assembled to determine a long list of potential targets, ranked in order of priority.

Which ones will ultimately be targeted will depend on when the telescope is able to observe them, Pontoppidan said.

An international project worth 10 billion dollars, James Webb was successfully launched at Christmas, and is now 1.5 million kilometers from Earth.

After the publication of these first scientific images, the first official observation cycle will begin.

James Webb must in particular make it possible to observe the first galaxies, formed only a few hundred million years after the Big Bang.

The telescope's mission should last at least 5 years, but the telescope has enough fuel to operate for more than 20 years.

© 2022 AFP