After a first “test” but already stunning image revealed on Monday evening, the James Webb Telescope revealed new color images on Tuesday.
A long-awaited first photograph, more than six months after the launch of the super telescope on an Ariane V rocket on Christmas Day 2021.
> Video – relive the launch of the rocket that launched the James Webb from Kourou, French Guiana:
The snapshot was unveiled on Monday evening by NASA in the presence of US President Joe Biden, who hailed a “historic” moment.
We were able to detect countless galaxies and stars against a dark sky background.
The universe as it was shortly after its creation
But above all, the snapshot allows us to observe the universe as it was… 13.1 billion years ago, shortly after the Big Bang. How? Because of the speed of light.
Specifically, what we see in this image is several billion light years away. So long that it took… 13.1 billion years for the light from these objects to reach the telescope.
Which is “only” 1.5 million kilometers from Earth: the information it sends towards Earth therefore only takes a few seconds to reach us, at the speed of light (about 300,000 km/s).
An impression of enormity in a very small piece of the universe
The image, teeming with luminous elements, appears to cover a very wide field. However, this is not the case: what this image shows, from Earth “could be hidden by a grain of sand held at arm’s length”, explains Eric Lagader, astrophysicist and president of the French Society for Astronomy and Astrophysics.
This little animation shows just how small the part of the cosmos captured by the telescope is:
In detail, the image shows dots in the form of a cross and luminous clusters. Some have an intense white color, others a darker orange or even red color.
The more objects appear red, the longer they are
“The light from the most distant galaxies is redshifted,” explains Eric Lagadec. “And the red galaxies are therefore furthest away” from the telescope.
The cross-shaped points are stars and the luminous clusters are galaxies. Each of them contains several tens of billions of stars. And probably an immeasurable number of planets, as described by Eric Lagadec:
This Tuesday, NASA revealed all the first images of the most powerful space telescope ever designed:
We were able to discover incredible photographs of two nebulae that illustrate the life cycle of stars, an exoplanet and a compact group of galaxies.
Each picture is a new discovery. Each of them will give humanity a view of the universe we have never seen before.
Bill Nelson, Executive Director of NASA
The last cosmic object whose observation was revealed on Tuesday is an exoplanet, that is, a planet orbiting a star other than our Sun, one of James Webb’s main lines of research:
It was not actually photographed, but analyzed by spectroscopy, a technique used to determine the chemical composition of a distant object. In this case, WASP-96 b, a giant planet made up mostly of gas.
In search of water vapor
By combining the data previously obtained thanks to other telescopes and those of James Webb, “we will probably be able to detect water vapor” in its atmosphere, estimates José A. Caballero, astronomer at the Centro de Astrobiologia in Spain and exoplanet specialist.
This data “will be interesting for me to see the possibilities of the telescope and the instruments”, he added, although he considers this first exoplanet a bit “boring”, and looks forward to less and less heat.
One of the primary missions of James Webb – a $10 billion engineering feat and the most powerful space telescope ever designed – is to explore the “early years” of the universe. Or rather, the first hundred million years: It is estimated that the Big Bang took place 13.7 billion years ago, and that telescope images show the universe 600 million years later.
20 years of fuel!
The result of a huge international collaboration, and in project since the 1990s, it is stationed 1.5 million kilometers from Earth.
The publication of these first images marks the beginning of an enormous scientific adventure that will span many years and transform our understanding of the universe: scientists from all over the world have reserved observation time with James Webb, whose program for its first year of operation is already been carefully determined by a committee of specialists and published.
The telescope has enough fuel to operate for 20 years. Around 20,000 people worked on this project around the world, creating a huge international collaboration.