On July 12 NASA revealed stunning first images taken by its James Webb Space Telescope. For scientists, the release of these images will lead to a better understanding of the history and formation of the universe and the potential discovery of life outside of Earth.
JWST is aninfrared telescope projected to be the primary observatory for numerous astronomers in the next decade. Unlike the Hubble telescope, JWST can view a larger range of infrared wavelengths, which are longer than visible light wavelengths. As objects farther apart in space emit light with longer wavelengths like infrared, JWST is necessary to observe these objects.
Prof. Lisa Kaltenegger,astronomy, is the director of the Carl Sagan Institute and explainedthat because JWST is bigger than Hubble, it can collect more light. This allows JWST to view objects farther from Earth that appear dimmer and smaller such as galaxies or planets orbiting other stars.
Additionally, because JWST can see objects farther from Earth, it can see farther in time than other telescopes. As light travels at a constant rate, the further an object is, the longer it takes for the light of the object to reach the spectator. While Hubble can view galaxies at the age akin to a toddler’s age, JWST can view “baby” galaxies, the oldest galaxies formed in the universe 13 billion years ago.
JWST harbors various technologies that help it produce detailed pictures of the cosmos. For example, the Near Infrared Camera acts as JWST’s primary imager, using instruments called cornographs to take pictures of dimmer objects around a central bright object. The cornographs block the bright object’s light to view the dimmer objects. This allows astronomers to determine characteristics of planets that orbit nearby stars. Another instrument JWST utilizes is the Fine Guidance Sensor, which helps the telescope to point precisely at objects and take high quality images.
With the assistance of its instruments, JWST was able to take five images significant to exploring the universe.
“Watching the images from JWST is a touching testament to the spirit of humanity. JWST is an international endeavor opening our eyes to new mysteries of the cosmos, showing what we can do together,” Prof. Kaltenegger said.
The first image is of galaxy cluster SMACS 0723, which shows thousands of galaxies in a part of the sky the size of a grain of sand. According to Prof. Kaltenegger, all these galaxies contain billions of stars or planets and the furthest light source in the picture is from 13 billion years ago.
This picture allows researchers to determine the galaxies’ mass, age, history and composition. In addition, the image, when viewed in the longer mid-infrared wavelength of light, shows the galaxies in different colors, which indicates different composition. For example, blue galaxies have many stars and little dust, while green galaxies contain hydrocarbons.
The second image displays a spectrum of WASP-96b, a gas giant exoplanet, which is a planet outside the Solar System. It shows the presence of water, clouds, and haze in its atmosphere. Using JWST’s Near-Infrared Imager and Slitless Spectrograph , an instrument that uses near-infrared light from objects to produce a spectrum, the components of the atmospheres of WASP-96b and other planets can be identified. The spectrum detects water, oxygen, carbon and temperature. Thus, astronomers can determine which planets may be suitable for life based on their atmosphere.
The third image depicts the Southern Ring Nebula, shells of dust and gas ejected from a pair of dying stars 2,000 light years from Earth. Each shell is a loss of mass from the fainter star of the pair, and the farther the shell, the older. With JWST, the nebula’s shells can be examined and, thus, help determine its history, composition and location. Additionally, the nebula’s expulsion of dust and material may become incorporated into forming stars or planets later on.
In the fourth image, a galaxy cluster known as Stephan’s Quintet lies 290 million light years away from Earth within the constellation Pegasus. It also captures the collision between these galaxies that results in new stars and potentially, new planets containing ingredients for life, according to Prof. Kaltenegger. The image provides insight to galaxy interaction, which leads to galaxy evolution and star formation.
JWST’s final image depicts the dazzling edge of the Carina Nebula seven thousand light years away, dubbed the “Cosmic Cliffs.” According to Prof. Kaltenegger, it reveals numerous forming stars and potential planets, giving insight into the formation process.
Although JWST cannot view surfaces of planets in high resolution due to its distance, it can determine their atmosphere compositions, which are influenced by planet surfaces. Prof. Kaltenegger will use JWST to examine planets in the Goldilocks Zone, a range of distances in which the temperatures allow water to stay liquid, from their stars.
Prof. Kaltenegger hopes to utilize JWST to continue the work of the Carl Sagan Institute and find life within the universe.
“My research shows the intriguing nuances of habitable worlds and how to spot signs of life on planets that are just a bit different than Earth,” Prof. Kaltenegger said.
Before JWST’s release of images, Prof. Kaltenegger worked with an international team of researchers from Portugal’s Instituto Superior de Agronomia and Técnico and Canada’s Université Laval in Quebec to create a color catalog for icy planet surfaces in order to find life on these planets. The team collected 80 microbes from the subarctic Canada Hudson Bay through ice and water samples. These microbes’ coloration may provide hints as to how to find potential signs of life on icy planets.
Additionally, as a member of the team that developed NIRISS, Prof. Kaltenegger will work with the NIRISS team to take pictures of planets orbiting TRAPPIST-1, a star lying in a galaxy 40 light years away.
“It is an amazing time in our exploration of the cosmos,”Prof. Kaltenegger said.
“Are we alone? This amazing space telescope tool is the first-ever tool that collects enough light for us to start figuring this fundamental question out.”