Space. What the fascinating images transmitted by the James Webb Space Telescope tell us

After an initial “test” but already stunning image unveiled Monday night, the James Webb Telescope unveiled new color images on Tuesday.

A long-awaited first photograph, more than six months after the launch of the super telescope with an Ariane V rocket on Christmas Day 2021.

> Video – relive the launch of the rocket fired by James Webb from Kourou, French Guiana:

We were able to discover countless galaxies and stars on a dark sky background.

The universe looked 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? Due to the speed of light.

Specifically, what we see in this picture is several billion light-years away. So far 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 to Earth therefore only takes a few seconds to reach us, at the speed of light (about 300,000 km / s).

An impression of immense in a very small piece of universe

The image, which abounds with luminous elements, seems to cover a very wide field. However, this is not the case: what this image shows could “be hidden from Earth by a grain of sand held at arm’s length,” explains Eric Lagader, astrophysicist and president of the French Society of Astronomy and Astrophysics.

This little animation shows 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 red-shifted,” explains Eric Lagadec. “And the red galaxies are therefore furthest away” from the telescope.

The cruciform points are stars, and the luminous clusters are galaxies. Each of them contains tens of thousands of billions of stars. And probably an immense number of planets, as described by Eric Lagadec:

This Tuesday, NASA unveiled all the first images of the most powerful space telescope ever designed:

We were able to discover incredible photographs of two nebulae illustrating the life cycle of stars, an exoplanet and a compact group of galaxies.

Each image is a new discovery. Each of them will give humanity a view of the universe we have never seen before.

Bill Nelson, CEO 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 research lines:

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 consisting mainly 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, assesses José A. Caballero, astronomer at the Centro de Astrobiologia in Spain and exoplanet specialist.

These data “will be interesting for me to see the possibilities in 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 James Webb’s primary missions – a $ 10 billion engineering achievement 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 telescopic 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 around the world have reserved observation time with James Webb, whose program for its first year of operation is already have been carefully determined by a committee of specialists and published.

The telescope has enough fuel to operate for 20 years. About 20,000 people worked on this project around the world, which created a huge international collaboration.

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