Exploring the Cosmic Dance with the James Webb Telescope

Launched on December 25, 2021, the James Webb Space Telescope (JWST) infrared observatory was designed to observe how galaxies form and grow and to look back into the universe to the era of the first galaxies and watch the birth of stars in unexampled detail. The 10 billion dollar instrument was also expected to explore the atmospheres of exoplanets and provide insight into the properties of some of the closest rocky planets.

Scientists had a lot to worry about as the instrument had a very complex and very sensitive nature, had to travel to the Lagrange 2 point 1.5 million kilometres away and perform a series of installation manoeuvres and fine-tuning on its own to start working. However, when the telescope revealed its first images in mid-July, it became clear that there was no longer a need to worry and that it would operate more effectively than expected.

Even with the first images, researchers began discovering tens of thousands of new galaxies more distant and more ancient than any galaxies we knew, some of which were more than 150 million years older than those previously detected and identified.

What has humanity’s sharpest eye looked into the depths of the universe shown us? Let’s take a look at the most important discoveries of the JWST and its contributions to our ever-expanding ocean of knowledge:

The Most Distant Galaxies

With a mission to observe the most distant galaxies in the universe, the JWST has shown us the oldest galaxies we have ever seen. Since looking forward and further in space means looking back in time, the telescope’s sharp eyes allowed us a glimpse into the past of our universe when it was only 350 million years old.

Scientists suspected that some of these galaxies, like the hundreds of others described by the JWST, were incredibly ancient. When they analysed the data from the device’s near-infrared spectrograph, they determined that the redshift values of some galaxies were above 13, which means that we see these galaxies as they existed less than 300 million years after the Big Bang.

Thanks to the JWST, we are able to find galaxies this far for the first time and spectroscopically confirm their distance from us.

The First Direct Photograph of an Exoplanet

Scientists discovered the first exoplanets in the 1990s. Today we know more than 3,000 worlds orbiting distant stars. Despite this incredible number, we were only able to observe about two dozen of them directly. Most exoplanets are so far away that they can only be detected by the dip in the light of their host star when they pass in front of the star. In September, JWST changed that, capturing the first direct image of an exoplanet.

The scientists used Webb’s two cameras, several filters, and coronagraphs that block the light of the central star to image the planet called HIP 65426 b, which was discovered back in 2017. This planet is a gas giant about 12 times the size of Jupiter and is extraordinarily far from its host star -about 100 times the distance of Earth to the Sun, and farther away from any planet in our solar system.

JWST with Other Instruments

The JWST also works in line with the other powerful instruments. While the Hubble Space Telescope (HST) predominantly makes observations in the visible and ultraviolet parts of the electromagnetic spectrum, with the ability to observe only near-infrared light, James Webb has a deeper infrared vision. For this reason, two galaxies known as VV 191 appear to interact in Hubble’s observations even though one is much more distant because the light from the distant galaxy passes through the closer one. On the other hand, James Webb can see through the dust of the closer galaxy and better map the spiral structure of the more distant one. Such advanced details can only be worked out with the help of observations in different parts of the electromagnetic spectrum.

The Chandra space observatory, which peers into space from orbit with X-ray glasses, is also among the devices James Webb is designed to work with.

 The Stephan Quintet consists of 4 galaxies in a complex cosmic dance and a fifth galaxy watching them from afar. Combining James Webb’s observations with the images taken by Chandra and Spitzer revealed a huge shock that heats the gas to tens of millions of degrees Celsius, as one of the galaxies passes through the others at speeds of around 2 million miles per hour.

The Atmosphere of Another World

JWST has given us access to detailed and interesting data regarding the atmosphere of WASP-39b, an exoplanet that orbits a star in the Virgo constellation. About 700 light-years from Earth, WASP-39b is a boiling gas giant the size of Saturn, on an orbit that is unusually close to its host star.

To observe the distant planet, the astronomers used three of James Webb’s instruments: the main NIRCam and two spectroscopes, called NIRISS and NIRSpec, which reveal the chemical composition of observed objects in the form of barcode-like fingerprints. The observations revealed the presence of carbon dioxide in the atmosphere of WASP-39b. This was the first time carbon dioxide was observed in an exoplanet’s atmosphere. The planet’s thick atmosphere was also found to contain carbon monoxide, potassium, sodium, water vapour and sulphur dioxide.

These studies also allowed scientists to test methods that could one day help detect life on other exoplanets. Predictions can be made by comparing the results of an atmospheric analysis similar to that conducted on WASP-39b with models of alien planets. For example, if spectroscopic analysis of the planet shows more oxygen than these models predict, it could be a sign of life.

Ice Giants

Neptune

JWST owes its impressive success to its optical systems that can achieve maximum potential resolution for most of the infrared wavelengths it observes. It allows astronomers to distinguish details that could not be detected by previous ground or space telescopes, stars so close to each other that they were once indistinguishable, and the structures of very distant galaxies. Even something close, such as the rings of Neptune can be seen with the most detail seen in decades.

The details of these rings seen by the researchers for the first time in the infrared have created quite an amazement that one could easily ask “Are we really looking at Neptune?” Furthermore, some dust rings that could not be detected during Voyager 2’s visit in 1989 were also revealed for the first time.

Because James Webb can see in the infrared spectrum, these new Neptune images show much more detailed gas, cloud, and storm formations instead of the blue sphere of methane gas clouds we are used to seeing.

Uranus

Following the impressive photo of Neptune, the JWST also captured a stunning view of Uranus, the other ice giant of our solar system. The new image shows us dramatic rings as well as bright features in the planet’s atmosphere. The Webb data reveals the observatory’s unprecedented sensitivity to extremely faint dusty rings that have so far only been imaged by the Voyager 2 spacecraft and the Keck Observatory with advanced adaptive optics.

When Voyager 2 looked at Uranus, its camera showed a nearly featureless blue-green ball at visible wavelengths. With Webb’s infrared wavelengths and extra sensitivity, we can see in much greater detail how dynamic the atmosphere of Uranus actually is.

Impossible Galaxies

One of Webb’s most compelling recent observations has been some really distant galaxies, whose formation we are yet to describe with the “formation of the universe” scenario we have developed so far.

Six massive galaxies newly discovered by the JWST contain nearly as many stars as the Milky Way, despite being formed only 500 to 700 million years after the Big Bang. Due to this fact, they were named “universe breakers” by the team of astronomers who identified them.

These galaxies did not have enough time as the early universe was not expected to organise itself so quickly. Considering that the Milky Way forms only a couple of stars a year, these galaxies must have formed hundreds of stars each year throughout their history. Unless another explanation can be found, they truly seem to push the boundaries of our understanding of cosmology.

The Deep Field

When the Hubble deep-field image was released 20 years ago, it made a tremendous impression. Focusing on a relatively empty part of the universe for a long time, the instrument revealed thousands of galaxies and changed our estimates of both the size of the universe and the number of stars and galaxies. Twenty years later, James Webb managed to impress us once again by sending much clearer and much more detailed images of the same region, and ten times faster than Hubble.

Captured by the JWST’s powerful Near Infrared Camera (NIRCam) instrument, the image helps astronomers piece together the history of the universe in the first billion years after the Big Bang.