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NASA has released the first color images of the James Webb Space Telescope. They are amazing.

Last year, before the launch of the James Webb Space Telescope, I wrote: “The largest space telescope in history is about to amaze us.”

Consider it mind blowing. NASA has finally released its first images from the space observatory. These images have been created for decades and come after years of delays and ballooning budgets. But they don’t disappoint. Consider this very first image released by the space agency on Monday:

The first image taken by the Webb Space Telescope shows in detail a section of the distant universe.
NASA, ESA, CSA, STScI, Webb ERO

What makes this image so mind-blowing is how small and how big it is at the same time.

It is small in the sense that this image is only a tiny part of the night sky. Imagine that you are holding out a grain of sand at arm’s length. The area of ​​the sky that the grain covers is the size of the area captured in the image above.

But it’s huge in the sense that almost every object in this image is a galaxy (apart from the bright, pointed starbursts that are the stars in the foreground). Think about it: there are at least thousands and thousands of galaxies in every piece of the sky.

And although it seems to us a flat image, this image reveals the depths of the universe and is a window in time. The faintest and smallest flashes of light in these photographs are images of galaxies that existed more than 13 billion years ago. almost at the beginning of time (this light has been traveling in space ever since). And not only Webb can take pictures of such old galaxies; space telescope can measure which elements those early galaxies are made up of.

This image looks like a sedimentary core. It shows the evolution of the universe over time in its many layers.

And this represents a huge improvement in the capabilities of the Hubble Space Telescope, which was the largest observatory in space before Webb’s launch. The Hubble Mirror is an impressive 7.8 feet in diameter. Beautiful golden Webb mirrors are 21.3 feet in diameter. Overall, this is more than six times the light collecting areaand when it comes to telescopes, the more light, the more detail.

You can already see the improvements Webb brings over Hubble. The Hubble Space Telescope has previously made similar observations of the same Webb Galaxy Cluster pictured above.

In the image slider below, the Hubble view is on the left. On the right, the view of Webb is more detailed. The fainter galaxies in the background are easier to see. You can also more easily see how some galaxies are more distinctly curved as a result of their light passing through the gravitational lenses of galaxies that are closer in the foreground. (Note: these images aren’t perfectly aligned, but you should still be able to see a stark difference in detail.)

Left view from Hubble. On the right is the same view from the Webb Telescope.

Webb’s other advantage over Hubble is the type of light it collects.

Light comes in many different forms. The human eye can only see a narrow band known as visible light, but the universe contains a lot of light outside of this range, including higher frequency and higher energy forms: ultraviolet light and gamma rays. Then there is low energy light with longer wavelengths: infrared, microwaves, radio.

The Hubble Space Telescope collects visible light, ultraviolet and some infrared. Webb primarily an infrared telescope, so it sees light at a longer wavelength than our eyes can see. It sounds tedious and technical, but it’s actually what allows Webb to see further back in time than Hubble.

Infrared light is often very old light due to a phenomenon called redshift. As the light source moves away from the viewer, it stretches out into longer and longer wavelengths, getting redder. This is similar to what happens to sound when a siren passes: the pitch rises as the siren approaches, then decreases as it moves away. because space is constantly expanding, the farthest objects in the universe are moving away from us, their light getting redder and redder before eventually moving into the infrared spectrum. Infrared radiation is invisible to the human eye, but Webb can capture it in great detail.


As the universe expands, it stretches light wavelengths along with itself, a process called redshift. The further away an object is, the more the light from it is stretched by the time it reaches us.
NASA/JPL-Caltech/R. Hurts (California Institute of Technology-IPAC)

On Tuesday, NASA released more images from Webb showing off its impressive capabilities. Here you will see the Carina Nebula, a star forming region. Infrared light is less obscured by cosmic dustand therefore the Webb telescope can detect more stars in this region than Hubble could. “Webb shows emerging stellar nurseries and individual stars that are completely obscured in visible light images.” – NASA explains.

The Carina Nebula as seen through the James Webb Space Telescope.
NASA, ESA, CSA and STScI

Here Webb notices a quintet of galaxies. “Webb reveals never-before-seen details in this group of galaxies” – NASA relay. “Glittering clusters of millions of young stars and starburst regions brighten the image.”

Stefan’s quintet of galaxies as seen through the Webb Space Telescope.
NASA, ESA, CSA and STScI

In another stunning image, Webb observes the remnants of a dying star in the South Rim Nebula. On the lower left, the nebula is captured in near-infrared, and on the right, in mid-infrared, each revealing a different detail of this cataclysm. The dim star at the center “sends out rings of gas and dust for thousands of years in all directions,” according to NASA. writes.

The South Rim Nebula, as seen through the Webb telescope, is near-infrared on the left and mid-infrared on the right.
NASA, ESA, CSA and STScI

This is just the beginning of Webb’s scientific mission. In the future, scientists hope to use it to see the very first galaxies, which contained the very first stars, and to understand the period of time called “space dawnwhen the universe first became transparent to starlight.

Before the cosmic dawn, the universe was shrouded in “dense, obscuring fog of primary gas”, explains the National Science Foundation. From now on, no light enters our telescopes. called the cosmic dark ages. (There is some background radiation from the Big Bang called the cosmic microwave background, a faint glow that shines on us from the pre-Dark Ages. But for the most part, the Dark Ages are a blank spot on our Universe timeline.)

Astronomers hope that Webb will help them understand the end of the dark ages and figure out what caused this fog to clear, ushering in a cosmic dawn.

Scientists are also excited to use Webb’s infrared capabilities to study exoplanets, meaning planets orbiting stars other than our own. Webb is unlikely to see the exoplanet directly, but he can observe the stars they orbit. When a planet orbits in front of a star, light from the star passes through the planet’s atmosphere like a filter. Scientists can study the quality of the light coming from this filter and use it to determine the composition of the planet’s atmosphere. And the team of scientists working on Webb has already done it. On Tuesday, NASA announced that Webb had discovered water. in the atmosphere from giant planet orbiting a sun-like star.

Achievements like the James Webb Space Telescope make me think that we, humanity, are part of a universe that looks back at itself. The big bang, the birth of stars, the formation of galaxies… we are as much a consequence of the physics and evolution of the universe as everything else that exists there. So when we peer into space with a telescope like Webb, we are closing a loop. We are building a tool that will perhaps make the universe a little more self-aware.

Webb, in its most basic function, allows us to see more of the universe and further into the past. This is just the beginning. There are so many things to see.

Further reading: Space telescopes.




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