Many of us, at some point, will have used even a short time one of the amazing photos taken by the Hubble telescope as wallpaper on your desktop or smartphone. The images captured during its, at times troubled, over thirty years of history made us dream, explore with more than imagination corners of the universe that we could not imagine being so fascinating. Let’s take for example the shots of the Eagle Nebulaa photo that has also become famous under the name of Pillars of Creation, through which we could see one of the places where the stars originate. Or of the Butterfly Nebulawhere we see the end of a star immortalized.
However, the last few days have shown us something completely new and sometimes revolutionary compared to what we have observed so far. During two separate events NASA showed us the future of space observationa new way to explore the far corners of the universe.
The James Webb Space Telescope
Launched on December 25, 2021 aboard a rocket Ariane 5 from the Kourou Spaceport in French Guiana, the James Webb Space Telescope it brings with it a series of technologies that make it the most technologically advanced celestial observation instrument ever designed by man, as well as being the largest ever launched into space.
His mirror with a diameter of 6.5 metersits heat shield the size of a tennis court and capable of eliminating interference from the heat of the Sun, the Moon and its own instrumentation, its ability to analyze the wavelengths of the infrared bandwill allow us in the years to come to better understand the universe around us.
Expectations towards him were high right away, his troubled history has given rise to more than one concern in the minds of its designers and those who have followed its vicissitudes with passion, but all this changed when NASA decided to reveal to the whole world the first exclusive images taken by the telescope, and not only those.
Deep Field
“This area of the universe portrayed in this photo is equivalent to a patch of sky the size of a grain of sand placed on the tip of a finger, held at arm’s length from a person here on Earth“. This is the comment of Bill Nelson, current Administrator of NASA, in introducing the first revealed image. In the presence of United States President Joe Biden and Vice President Kamala Harris, Nelson showed the first Deep Field shot from JWST. It’s about SMACS 0723a cluster of galaxies already photographed by Hubble but which now appears with an enormously higher level of detail than that provided by the predecessor of the JWST.
The image shown is the result of the combination of multiple shots taken using different wavelengths and unified through an elaboration that lasted about 12 and a half hoursa much lower time than that required by Hubble for similar operations, and thanks to the combined use of the Near Infrared Camera (NIRCam), the telescope’s main camera, and the Mid infrared instrument (MIRI), is populated by a series of details able to tell much more than expected about this densely populated cluster of galaxies.
Some of the galaxies visible in the photo date back to when lhe universe had not yet reached one billion years of lifetheir light has taken billions of years to reach us with dilated wavelengths due to a phenomenon called Cosmological redshiftwhich means that the light emitted by a moving object has a longer wavelength than it had when it was emitted.
The photo allows us to make a real journey through time, showing us what SMACS 0723 looked like 4.6 billion years ago, with the combined mass of the galaxies which, acting as a gravitational lens, allows us to observe those celestial bodies so young and dating back to when the universe was still very young. This image alone would have been enough to leave everyone in awe for a long time, but what was subsequently revealed only amazed those who observed the event even more.
Here the link for theimage high definition.
A look at the atmosphere of an exoplanet
The comparison of the analyzes conducted on the starlight filtering through the atmosphere of a planet as it passes in front of the star around which it rotates and the unfiltered light as it is alongside the star, is what allows us to obtain one transmission spectrum. It is able to return data concerning the atmosphere of a planet, allowing us to know some of its characteristics.
It is not the first time that the atmosphere of an exoplanet has been studied, Hubble himself was able in 2013 to identify traces of water in a planet’s atmospherebut the information obtained thanks to the advanced tools of the JWST mark a turning point in this kind of observations. WASP-96 b it is one of over 5,000 planets identified in the Milky Way and, thanks to the most recent analyses, it has been possible to identify water, the presence of mist and clouds in its atmosphere.
Studies have already been conducted in the past, but never before has it been possible to arrive at such a thorough analysis of the gases that make up the atmosphere of this huge and very hot gaseous planet about away from us 1150 light years.
The possibility of carrying out such in-depth studies gives way to a new era of exoplanet exploration, researchers will be able to obtain information capable of making them understand their history and evolution and why not, maybe it will help them identify a possible new world habitable for the human race.
Here the link for theimage high definition.
The end of a star
The magnificent shot of the planetary nebula NGC 3132also known by the name of Southern Ring Nebula, it’s not just a photo that could very well be framed and displayed in our homes. JWST, and Hubble before it, immortalized the final part of the life of a double star systemso far only hypothesized and now clearly visible, which for thousands of years has emitted rings of gas and dust into the space around it, generating this magnificent nebula which we can now admire in all its splendour.
The two stars in the center behave differently, which is due to their different evolutionary stage; they they revolve around each otherbut while one, the brightest, is in a less advanced stage of its evolution, the other has already been expelling the material that we see immortalized in the shot.
What we have is a front view of it, but if we could rotate it we could see a structure that would remind us of two bowls joined at the bottom.
The James Webb, through its instrumentation, will be able to tell us which molecules are present in the released gas shells and their location, allowing scientists to increase understanding of these objects. This could happen, for example, through an accurate observation of the gaseous layers released by the stars. Understanding their temporal sequence and composition will provide decisive information on their history.
Here the link for theimage high definition.
Stephan’s quintet
What we see in front of us is a mosaic obtained merging around 1000 different images taken by James Webb. The result is a shot with a level of detail never seen before, which allows us to study this cluster of galaxies in a different way.
Discovered in 1877 by the French astronomer Édouard StephanStephan’s Quintet is a very active compact group of galaxiescharacterized by the interactions between its components. Although we talk about “quintet“, however, it should be noted that only four of them are actually close. The first, the one located further to the left and named NGC 7320 is located 40 million light years from Earthwhile the others, NGC 7317, NGC 7318A, NGC 7318B and NGC 7319, are located about 290 million light-years away.
They are engaged in a kind of “cosmic dance” and the JWST was able to capture a moment that we could define as dramatic, that is, the one in which NGC 7318B breaks through the cluster generating huge shock waves. The topmost galaxy of the group, however, NGC 7319, hosts an active galactic nucleus, a supermassive black hole 24 million times the mass of the Sun that is devouring the material around it.
The new James Webb instrumentation made it possible to “dissect” the nucleus going beyond the blanket of dust that surrounds itbeing able to see the luminous outflows guided by the black hole in a level of detail never achieved before.
Here the link for theimage high definition.
How a star is born
The last photo shown during the conference can safely be called a “grand finale“.
We’re talking about an incredible shot that portrays the edge of a star formation area called NGC 3324 (here the link for theimage high definition), located within the Carina Nebula in the constellation of Carina, at a distance of about 7600 light years.
What we see at first glance may resemble a mountainous landscape, with peaks from which a thin mist slowly rises. What we are observing, however, is actually one basin carved by ultraviolet radiation and stellar winds emitted by some large and recently formed stars located above the photographed area. the “peaks” that we see reach heights of about 7 light-years.
The very haze we see rising from these peaks is material eroded from the nebula by the ultraviolet radiation we discussed earlier.
The advanced instrumentation of the JWST not only allows you to see elements and details that previously could only be imagined, let’s think for example of those stars that were previously invisible because they were covered in thick blankets of dust and which we can now see emerging from the nebula, but it will prove essential in addressing some questions that modern astrophysics has been trying to answer for some time: what are the factors that determine the number of stars that can be generated by an area like the one photographed and analysed? What determines their mass? What are the effects of minor stars on the material clouds that make up the nebulae?
These, and many other questions, scientists hope to be able to answer in the near future.
What we have witnessed in these two events is an appetizer that NASA has provided us with what we may see in the coming years. New discoveries, new revelations, and why not, even new worlds, are ready to be discovered and shown to the whole world. And we, therefore, just have to wait for all this while we gaze up at the wonders that light up our night sky.
Image credits: NASA/ESA/CSA/STSc
James Webb Space Telescope: a futuristic look at the Universe