Today we saw the publication of the first batch of images taken by the James Webb Space Telescope. This is something we have both been waiting for for almost 25 years. In those days, we were analyzing the first Hubble images of the distant universe and the details they revealed were shocking compared to anything we had seen in the terrestrial images.
It looks like the bar has risen once again and Webb is poised to herald a new era for astronomy and space research. Its large mirror helps it produce images two or three times sharper than Hubble’s and that go much deeper into space (meaning you can see weaker sources).
Webb can also see much redder infrared wavelengths, opening up a new view of the universe. This is especially important for studying the early universe because of the “cosmological redshift,” a process that refers to the stretching of light (with the expansion of the universe) as it travels through cosmic space.
It is also useful for studying fascinating sources, such as the planets that surround nearby stars and the regions where stars form.
We’ve written before about the huge technical challenges involved in building Webb and his journey into orbit. Now, with the long-awaited first images in our hands, let’s take a look at what they show.
Read more: NASA’s James Webb Space Telescope has reached its destination, 1.5 million km from Earth. Here is what happens below
Intense clarity
In a preview, U.S. President Joe Biden presented the first image of Webb’s “deep field” yesterday. This is the huge cluster of galaxies SMACS-0723 that contains thousands of galaxies clustered around a super bright central galaxy located in the center.
The southern giant cluster SMACS 0723 was captured by Webb. NASA, ESA, CSA and STScI
You will immediately notice the many elongated arcs, which represent background galaxies that have been “slow gravitational” as a result of the mass of the cluster. In other words, the enormous forces of gravity at play have caused galaxy light to be distorted (stretched) and amplified, providing a much improved picture of the distant universe.
The clarity is amazing, especially when it comes to the structure of the lens images. Here’s an enlarged view of a small region, compared to a similar Hubble exposure time image:
A comparison of Webb (left) and Hubble (right) in their view of the same region. This is an expanded area of Webb’s deep field. Adapted from NASA, ESA, CSA and STScI images
The enlarged images above portray a region of the deep field that contains a spiral galaxy that astronomers have affectionately called “The Slug.” It is found several times beyond the SMACS-0723 cluster.
But our eyes were more attracted to the very thin bow just above (marked with arrows). This small snippet demonstrates Webb’s power. This bow was barely detected by Hubble, but Webb clearly sees the “pearls on a rope.” They are likely to be individual star clusters in the extremely distant little galaxy.
We can see equally amazing details all over the deep field. For point objects, Webb is expected to be more than 100 times more sensitive than Hubble, and this definitely proves it.
The field is also littered with some faint red objects, which are already catching the attention of experts. Some of these could potentially be the most distant galaxies, where light has taken longer to reach us.
Revealing hidden elements
Webb is also capable of extremely sensitive infrared spectroscopy, where light is decomposed into wavelengths to reveal the composition of an object.
While Hubble is very poor at this, Webb does it well, as shown below by the spectrum of the massive planet WASP 96b. Located about 1120 light-years away, this planet weighs about half the mass of Jupiter.
Webb captured the spectrum of the exoplanet WASP-96b, a hot gas giant. NASA, ESA, CSA and STScI
Spectrum drops reveal the presence of water vapor in the planet’s atmosphere. Now, WASP 69b is unlikely to host life due to its proximity to its parent star. However, this demonstration is very exciting, as the same method can be applied to 5,000 or so other known exoplanets.
With spectroscopy, we will eventually be able to detect possible life signatures such as ozone and methane.
Seeing dust and gas
The third image is of the southern ring nebula, about 2,000 light-years away in the Milky Way. This image shows Webb’s average infrared capability (which is again well beyond Hubble’s range).
The planetary nebula of the South Ring, with an image of the near infrared on the left and one of the middle infrared on the right. NASA, ESA, CSA and STScI
It is a classic example of a “planetary nebula” (a wrong name since there is no planet) in which the central star has transformed into a small white dwarf by ejecting its outer layer. This happens at a speed of about 15 miles per second, sending rings of gas and dust.
The brightest star in the center is actually an accompanying star, and the white dwarf is the faintest pair that can only be seen in the middle infrared, as it is obscured by dust. The average infared also highlights the dust that is forming in the expanding gas.
The fourth image below shows Webb’s view of nearby galaxies. Here we see a famous group of galaxies called the Stefan’s Quintet, located about 290 million light-years away. The five galaxies are very close. Four are interacting with each other and triggering abundant star formation.
Stephan’s Quintet is a compact group of interacting galaxies. NASA, ESA, CSA and STScI
The red stripes and clusters show the location of the formation of new stars using the associated dust. The detail of the dust distribution and the tug-of-war that takes place between the galaxies comes out of the picture. And the middle infrared reveals the light of a supermassive black hole in the center of the upper galaxy.
What also stands out is the vast sea of distant galaxies in the background. We look forward to seeing it in all of Webb’s images, even when Webb points to sources within the Milky Way. This is because infrared light passes through the dust. Webb’s infrared detection capabilities are so sensitive that you will see directly through objects in our galaxy.
This means that distant background galaxies will bombard all Webb images. See if you can see them in the pictures of the South Ring and Carina.
And finally, we have Webb’s tribute to Hubble’s famous Pillars of Creation image.
The Carina Nebula, a cosmic nursery surrounded by gas and dust. NASA, ESA, CSA and STScI
This infrared view shows the Carina Nebula, a stellar gas and dust nursery 7,600 light-years away where new stars form and destroy its birth cloud.
The image is extremely complex and the complex swirls of dust, gas and young stars are mind-blowing. Astronomers will probably need many years of hard work to figure out exactly what is going on here.
Just this handful of preview images, a few days of work for Webb, have given astronomers a wealth of new data that will drive years of research. And that’s just the beginning.