The James Webb Space Telescope has finally managed to deploy its full potential and has pointed its main mirror at five different targets decided in secret by NASA. However, if he was not surprised by the panoramas revealed, perhaps it is because he had already seen them before, the eyes of the Hubble Space Telescope had already landed on them years ago. But a comparison between the before and after images will make us understand that the power of the James Webb is actually a milestone that is marking a new dawn in the era of astronomy and the science of deep space exploration.
What did the James Webb Telescope photograph?
July 12, 2022 finally came the day when the first images taken by the James Webb Space Telescope (JWST) were revealed. From the beginning, the researchers in charge of the JWST chose to aim towards five specific objectives:
But all these objectives had already been captured by the Hubble Space Telescope and although it may be a bit of nostalgia, the truth is that the observer who for more than three decades gave us the best views of the Universe is now being surpassed by James Webb. That is what science is about, always progressing with a view to new discoveries that help us understand the reality we inhabit and with JWST a new era has just begun.
Gravitational lenses
The first image revealed was the deep field photograph centered on a massive galaxy cluster. In it you can observe thousands of galaxies in the deep Universe very close to the galaxy cluster SMACS 0723. He had already given us an image similar to this one, however, the differences between the two are abysmal.
In the first image taken by Hubble you can see a composition in 7 filters that cover both optical and near-infrared wavelengths and which was taken in a total of 3.4 hours. On the other hand, the James Webb had a total observation time of 12.5 hours and collected data with its near and mid-infrared devices. The main difference between the two photographs lies in the sharpness of the galaxies; what previously appeared as spots can now be seen with their well-defined shapes: spirals, ellipticals or ringed galaxies.
WASP-96-b star system
The system has as its host star a G-class star very similar to our Sun in mass, radius and temperature. The exoplanet WASP-96-b orbits around it, which is similar to Jupiter, although with half its mass, however, it has a quality that has made it special for astronomers: it is practically free of clouds.
The proximity to its star means that its atmosphere has an average temperature of just over 1000ºC and since it is a gas giant, it is expected to be rich in cloud formations like Jupiter itself, but this is not the case. Although the exoplanet WASP-96-b had previously been observed, it had never been possible to see the composition of its atmosphere, until now that James Webb has revealed that there is a lot of it!
Southern Ring Nebula
Nebulae are indicators of a dying star. When a star similar to the Sun dies, it does so in a peculiar and very striking way. First, gently let go of its outermost layers, which generate a preplanetary nebula rich in gas. Then the core of the star collapses to a size no larger than that of our planet, yet it contains within it all of one solar mass. This contraction causes the stellar remnant, now converted into a star, to heat up to such a degree that it ionizes and expels the material already present on the outskirts. The result is the beautiful nebulae that we have previously observed thanks to Hubble.
The image above shows us the Southern Ring taken by Hubble, compared to the images below which are the most recent images from James Webb. The difference is very clear, while in the first one only a star is observed in the center of the nebula, one of the JWST shots reveals that it is actually a binary system, it also shows us a remote spiral galaxy hidden in the left side. And not only that, one can almost swear that the filaments of dust and gas are palpable thanks to the great sharpness.
The Stephan Quintet
This is the first compact group of galaxies discovered 150 years ago which is surprising since it is 290 million light years away. Within it there are two galaxies in the process of merging that are surrounded by two other galaxies that also interact gravitationally with each other. However, what appears to be a quintet from the terrestrial view is actually something else; one of the galaxies is 40 million light years away from its companions.
The galaxies that collide while merging are expelling gas, leading to the formation of new stars and also generating the large flow of material that can be observed at a wide variety of wavelengths thanks to the telescope devices. Compare for yourself the Hubble result above and the new James Webb image below.
The Carina Nebula
This is a large nebula that is located within our own galaxy, but it is surprising as it gives us explosions of electrifying colors. The formation of stellar dust and ionized gas is very extensive, with 300 light years from end to end, which is why the James Webb Space Telescope focused its mirror towards a special region within Carina called NGC 3324.
This area is known by the special name ‘Cosmic Cliffs’ because of the way the gas is arranged and which contrasts with the bright stars in front and behind it. The best way to admire the scientific progress is to simply take a look at Hubble’s previous best shot of the ‘Cosmic Cliffs’ and James Webb’s new view. If you stop to admire in detail, you will be able to see a plethora of objects that are not present in the first image and that we can now analyze in great detail.
*Image credit: NASA/ESA/Hubble Heritage/James Webb Space Telescope.