Recently in mid-July 2022 we began to see images from the James Webb Space Telescope. The new images are generating excitement and new questions in the scientific community. It is always exciting when new technology allows us to see something mankind has never seen before. The more we discover, the more new puzzles and mysteries are encountered as well. First of all, who was James Webb? He was administrator of NASA during the Apollo Mission years and gained a great reputation for helping accomplish important discoveries in space science. To go to the NASA official website for the James Webb Telescope, see https://www.jwst.nasa.gov/.
The James Webb Telescope (or JWST) is an infrared telescope and the successor of the Spitzer Space Telescope. Infrared telescopes are more effective from in space where they can be kept very cold. The JWST has several sheets of material that shield it from heat radiating from the Earth and the Moon. It has been placed at a special location known as L2, which is one of the “Lagrange Points” for Earth. In this location gravity makes it quite stable and it is never in direct Sunlight since Earth lies between it and the Sun. The James Webb telescope is said to be so sensitive that it could detect the heat given off by a bumble bee at a distance to the Moon! The JWST has 18 mirrors that are very precisely aligned to look in the same direction. Thus it collects digital image data and the data is magnified in a way that is essentially like stacking the 18 images on top of each other. There are three ranges of infrared wavelengths in the electromagnetic spectrum that can be viewed by the Webb telescope. Since all these wavelengths are invisible to our naked eyes, scientists essentially shift them to the visible range as desired to allow us to see them. Thus, the images generated do not show the objects in their “real” or “natural” colors, rather scientists can pick the colors to show different types of detail, depending on what they are wanting to study. This is how an infrared telescope is used and it makes for some beautiful images that are interesting to compare to the images from other telescopes like the Hubble Space Telescope, for example.
Webb’s First Deep Field
The Hubble Space Telescope was famous for its “Deep Field” images in long exposures of a piece of ‘dark’ sky. So, it’s not surprising one of the first images released on July 11 by the JWST has been called the Webb’s First Deep Field (shown below cropped and resized). It is a composite image that took a total of 12.5 hours. It captures galaxies farther away than anything the Hubble Space Telescope could obtain. It is mostly an image of galaxies, but there are some stars at relatively nearby distances that show up with spikes. The stars with diffraction spikes are not important, they are only an artifact of the telescope. The telescope is really looking at what lies behind the stars with spikes. Near the center of the image to the lower right of the large spikes is galaxy cluster known as SMACS-0723. This galaxy cluster is massive enough to bend the light from galaxies behind it. So, the galaxy cluster is magnifying and bending light from the galaxies behind it. This is an example of gravitational lensing, something Einstein predicted. The lensing effect causes the distant galaxies light to be smeared out in an arc. The arcs look almost concentric around the large cluster.
Next is a very famous group of galaxies that are interacting known as Stephen’s Quintet. It gets its name from five galaxies. In the James Webb image, three of the large galaxies show up in somewhat different colors, one greenish, one blue, and the one on top is purple and reddish. The blue elliptical shaped galaxy is nearer to us than the others. But these galaxies are distorting each other’s shapes and pulling gases and stars off of each other. The one above the others with red and purple apparently collided with the greenish one. The JWST provides a unique view of Stephen’s Quintet. This image is from the MIRI instrument, which is seeing mid-infrared light. This means it is looking through some layers of dust and gas to see deeper inside.
The JWST image of Stephen’s Quintet above is interesting to compare with another image of the same thing, below. The image below is Stephen’s Quintet viewed with a combination of X-Rays and Visible light. There are distorted galaxy arms and a blue shock wave visible in this image that are not visible in the James Webb image above. This shows how the MIRI instrument can see through outer material. The same region of sky around Stephen’s Quintet can look very different, when you are seeing different portions of the electromagnetic spectrum. There are actually more than five galaxies in these images. Astronomers have been fascinated by the Quintet for a long time.
The Southern Ring Nebula
Next is an interesting pair of images, both from the JWST. The Southern Ring Nebula is shown below using two different ranges of wavelengths in infrared light. The left image is from NIRCam, the James Webb telescope’s near infrared camera. This camera uses lower wavelength light, which is of higher energy. Then the image on the right is the MIRI instrument, for mid-infrared light. The mid-infrared uses higher wavelengths, which are of lower energy. So, its like NIRCam sees the hotter material and MIRI sees through the outer layers to the cooler material within. The Southern Ring Nebula has two stars within it that orbit each other. The two stars can be seen in the image on the right. The star that looks less bright has already shed some of its material to make the nebula. The other star (brighter) may do the same, some day. We are basically looking at the nebula end-on. If we could see it from a side view, it would look like two bowls stuck together at the bottom, with a hole in their centers where the stars are. Space telescopes not only help us see what we could not see with the naked eye, they allow us to highlight different elements in the gases or see particular features by studying the light spectrum from the object.
NIRSpec and Spectroscopy
One of the great technical innovations with the James Webb telescope I think is what’s called NIRSpec, for near-infrared spectroscopy. Spectroscopy breaks down or splits the light into its component wavelengths (like a prism but JWST has something way beyond what a prism does). So, spectroscopy allows astronomers to determine what chemical elements are present in what they see. What is more, the JWST NIRSpec instrument can observe 100 objects at the same time! There is a sophisticated micro-shutter system operated magnetically where each micro-shutter is about the width of a human hair. With this system two objects may be near each other in the sky but one could be blocked out and the other measured in a very precise way. The spectroscopic measurements of the JWST will be very important for study of nebulas and dust, extrasolar planets, and other objects. I’m particularly interested in what the Webb telescope discovers about exoplanets. Already, the JWST has done transit measurements of one exoplanet, WASP-96b. This exoplanet is only 1/9 of the distance to its star as Mercury is to our Sun. It is a gas planet of about ½ of the mass of our planet Jupiter but it is about 20% larger than Jupiter in size. It is very “puffed up” and close to its star. WASP-96b requires only 3 ½ Earth days to orbit its star. The Webb telescope gathered spectra as WASP-96b passed in front of its star. This spectra showed very clear evidence of water vapor in the planet’s gases. This is not the first evidence of water in an exoplanet but the extraordinary thing is the clarity of the data from the Webb telescope.
So far the main surprise to scientists from the James Webb Space Telescope comes from very distant galaxies that have been detected. There’s likely to be much more debate in the scientific community about these findings. The JWST has detected evidence for the most distant galaxies ever observed. The greatest distances in the universe are often expressed in terms of redshift. The redshift is expressed as a number; before the JWST, the most distance galaxies might have had a redshift value of 11-13. But even though it’s been only a few weeks since images started being released, the JWST is making a stir over distant galaxies. In some things our beliefs tend to determine what surprises us. Thus, there’s a need to understand a bit about Big Bang theory to understand what is surprising about the JWST images.
In the Big Bang theory, the universe begins with a hot fireball and a very rapid expansion of space. In the Big Bang model, it takes a few hundred thousand years for the expanding fireball to cool down enough that hydrogen atoms can form. When hydrogen can form and remain stable this is known as the decoupling of matter and radiation. From this time forward, the universe cools down as it expands. But all there is initially is hydrogen gas. There were no stars or galaxies or nebulas. But there were regions more dense than others and it is thought that gravity would begin forming clumps of matter. There has been a long debate among cosmologists over which came first, stars or galaxies. The general consensus today is that the first stars formed first, perhaps often in clusters, and then they collected together into galaxies. This is a process that requires a lot of time. The process is ill-defined actually and is very much still a mystery to scientists. How much time would it take to form the first galaxy? It’s thought that the earliest stars may have formed about 180 million years after the Big Bang. This means that in Big Bang theory, after the universe expands and cools down, there would be a period in which there are not yet any stars or galaxies. Then if the above scenario is correct, stars would have to form and then collect together into galaxies. So this period in which there was not yet any stars or galaxies has been referred to as the “dark age” of the universe.
The significant thing about the JWST is that it is thought to be able to see back to about what would be the approximate end of the “dark age”. So has JWST seen the end of galaxies? Not yet. Case in point is an object labeled as CEERS-93316; it is known officially as a “galaxy candidate.” Its redshift is 16.7, which scientists would say this puts it at about 250 million years after the Big Bang. There may be other “candidate galaxies” detected by JWST with redshifts of as much as 18. We may have to wait and see if these numbers are confirmed by other researchers. But, this is way out there!! By known effects such as gravity, it is challenging to explain how galaxies could form so early after the Big Bang. JWST will give better information on these distant objects than we have had before, thus these distant galaxies are going to be objects of much scrutiny. One scientist studying CEERS-93316 expressed the problem as below:
“The observations of this galaxy push observations back to the time when we think the first galaxies ever to exist were being formed. Already we’ve found more galaxies in the very early Universe than computer simulations predicted, so there is clearly a lot of open questions about how and when the first stars and galaxies formed.”
(To read more on this go to https://phys.org/news/2022-08-farthest-galaxy-broken-million-years.html )
Unlike what many Christians in the sciences say, I think the Bible conflicts completely with the Big Bang. The Bible doesn’t describe technical details of the beginning of the universe but it does give a time frame. The Earth and universe were completed in a week, from God’s miraculous activity. This implies that galaxies did not require a long process to form from gravity collecting stars together. Everything was complete and ready for the first man and woman when they were made on the sixth day. Thus, I suspect JWST will not see the end of galaxies. The most distant galaxies will look like galaxies usually look. But there could be surprises; there always are when we get to see with new technology. I think believing God created miraculously is more believable than believing that natural forces and processes did it all. Natural processes are just not up to the task of forming a universe.
Images: Public domain from NASA & the Space Telescope Science Institute (cropped and resized)