The people are here! After 25 years of designing, planning, building, launching, unfolding, and testing, the first science images from JWST have been released and show the full promise and spectacular nature of what this mighty observatory can achieve.
The purpose of the telescope is to see light with longer wavelength than our eyes can see. We will have a better view of the stars, planets, brown dwarfs, and more thanks to the fact that we can see the dust that is scattered between them.
The large mirror, made up of 18 hexagonal smaller mirrors, gathers a lot of light and provides a sharp view of the universe, so the images are clean and high-resolution, and the battery of filters means we can convert them into color images.
Your eyes and brain are on hold. Let's get going!
The gas and dust ejected from a star that was once much like the Sun but ran out of fuel in its core and died is called a planetary nebula. The central star blew away thick layers of material, exposing its hot core which blew hotter and faster gas into the ejected stuff. A big bubble was carved into it.
As the material expands, it can be seen in the NIRCAM image in orange, thick and structured. The hotter ionized gas is seen in the picture. The biggest revelation is that the star in the center is a pair of stars, not a single one. The second star can't be seen in shorter wavelength.
The way the gas was ejected may have been shaped by the motions of the planets. Astronomers will be able to understand the circumstances under which stars like the Sun die when they see these images from the JWST. The death of a star shows how it can help the next generation of stars.
Stephan's Quintet is a small group of interacting galaxies that are 300 million light-years away. There is a foreground galaxy aligned with the more distant group.
The NIRCAM image shows some of the cool gas and dust in the group, as well as some of the stars that are deep in the process of colliding. There are streamers of material called tidal tails that can be sent out from the two galaxies.
The center of the galaxy is very bright, and that means we're seeing the light from a black hole, eagerly gobbling down gas and dust. The material is very hot and glowing as it falls in. Images like this can give a lot of information about this process, like how massive the black hole is, how much material it's eating, what happens to that matter as it falls in, and how some of it is blasted away.
1,100 or so light-years from Earth is a Sun-like star with a very un-solar system-like exoplanet around it. The planet WASP-96b is half the mass of our own Jupiter, and it is only about 7 million km away from the star.
The atmosphere of WASP-96b is very hot. A transit occurs when the planet passes in front of a star. The light from the star goes through the planet's upper atmosphere to reach us. The air on the planet is very rich in atoms and Molecules. If we take a spectrum of that light, breaking it up into hundreds or thousands of colors, we can see how bright the planet is.
WASP-96b lacks clouds so we can peer deeper into its atmosphere. The spectrum taken by JWST shows the presence of water in the atmosphere. The dips in the spectrum are where steam is absorbed. It lets us know how much is there. There are some clouds in the sky of WASP-96b because the dips don't match the models of a cloudless atmosphere.
We've seen transiting hot exoplanets before, but this is the first time we've seen it in theIR. The presence or lack of things like silicates, methane, and more will be revealed by the further spectrum of other planets. It is more difficult with smaller planets. Future observations could show what's happening in the atmosphere of planets that are trillions of kilometers away.
There is a massive cloud of gas and dust in the southern constellation of Carina. It is one of the most active star-forming factories in the world.
You can see a lot of stars in this image. Radiation and winds of particles destroy the gas and dust. This leaves behind a wall of material with dense material below and less dense material above. It resembles a mountain ridge or a cloudbank.
Dozens of stars are being born there, some blowing away their birth gas, others still enshrouded in the materials that are forming them.
The devil is in the details when it comes to star birth. High-resolution images like these will help us see the bulk process better, and the data from the individual stars will give us a lot of information about how stars switch on, what happens to the material around them, and how some of that material will form planets.
SMACSJ0723.37327 is a collection of hundreds of galaxies that are located at the center of gravity. It is 4.5 billion light years away from Earth.
This image is a little hard to understand. The stars that have sharp objects with spikes are all in the same place. Do you see any fuzzy things? All of them are billions of light years away. There are many of them in this picture.
A number of thousands.
Some of those are part of the SMACSJ0723.37327 cluster. There are some blobs in the cluster. There are dozens of elliptical galaxies, which can be seen smeared out into structures. The cluster is visible from Earth, but those are far away.
The light coming from objects behind the cluster is warped by the mass of the galaxies in the cluster. They can be drawn out like arcs. Some of the shapes in the cluster are weird.
Many of the distant galaxies are far away than we could normally see without the lensing effect. Each of the unrelated background galaxies has billions of stars in it.
While this looks like a lot of similar Hubble images, the big difference is that this is an IR image, which has a wavelength of around 1 micron. The Hubble Deep Fields had a lot of exposure time. The image was taken in just twelve hours.
The arcs and smears are eye-catching, but the red dots are what I'm most interested in. The Universe was a toddler when those were most distant. One of the biggest contributions JWST will make to astronomy will be the ability to understand the universe's activity back then.
Where are those red blobs? We can look at the features of that spectrum to find out what elements are in it, as well as other things.
The universe was 700 million years old when light left it. Neon and oxygen are found in stars and are blasted out into the universe when they die, so even at this young age the universe has been through at least one generation of stars being born and dying.
The bending of spacetime, the mass and structure of SMACS 0723, and the images of stars forming in the distorted background are just some of the things I could write about.
I'll leave you with a simple thought, one so straightforward and profound that it is both easy and difficult to comprehend.
The image is over two minutes in length. The full Moon on the sky is 30 minutes across, 15 times larger than this image.
How large is 2.4 arcs minutes? The same angle is subtended by a half- millimeter-wide grain of sand on your finger. Bring your arm out in front of you by holding that mote up on your finger. There is a tiny grain of sand that blocks all these thousands.
Think about how much bigger the sky is than the sand. The entire sky can hold 25 million pictures. The image is a small fraction of the Universe, yet it shows wonders and delights.
When the JWST stares at a single spot in the sky for a long time, what will we see? There are hundreds of billions more to be investigated.
You will see why astronomer do what they do once you understand that.
We want to understand all of the universe. We have taken a huge step forward in doing that.
Due to the controversy over the observatory's name, I will simply refer to it asJWST. The initialism will suffice until NASA reconsiders the name.
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