And after much waiting, NASA’s new promise has a date set to go to the skies: December 18, 2021. Described as the “largest, most powerful and complex space telescope ever built and launched into space” by the agency itself, James Webb Space Telescope (JWST) will have 6,500 kg and mirror segments that combined are 6.5 meters in diameter. NASA also guarantees that the space telescope will alter our knowledge of astronomy!
In the image we can see the James Webb Space Telescope from above, being possible to identify the segments of hexagonal mirrors. For a sense of scale, Source: NASA
Professional telescopes are real time machines! Since light travels at a finite speed, traveling through the Universe takes time. Light from a star 4 light years away takes 4 years to reach us. This means that the light we see today was emitted 4 years ago and is the past of the star. Thus, the farther away an object we can see, the older its light and the farther we are looking into the past. With James Webb it will be no different!
As the largest space telescope ever launched, the James Webb will guarantee essential resolution at some wavelengths, such as infrared. With this ability and sensitivity, we will get new clues about how the first stars and galaxies formed!
Schema illustrating the James Webb Telescope’s ability to look into the past of the Universe. At the top we see the current moment with the Telescope. Going down in the image, we walk to the past and we can see a little of the evolutionary history of the Universe after the Big BangSource: NASA
After the Big Bang, what existed in the Universe was just particles, such as electrons, protons and neutrons. With the expansion and cooling of the Universe, these particles began to unite, forming atoms like Hydrogen and Helium. How exactly matter came together to form the first stars and galaxies is still unknown! With James Webb it will be possible to understand the birth of these first stars and galaxies!
Understanding how the formation of the first stars happened is fundamental to understanding how the chemical elements needed to build life were formed! Stars are big factories of chemical elements. They transform simple elements into more complex elements, forming elements such as carbon, oxygen, nitrogen and others. Before the first stars there was only Hydrogen and Helium, so studying these stars will help you understand how life in the Universe was possible!
But it’s not just the past that we’re going to look at, the JWST will also look at the birth of stars and planets and will make it possible to study the atmosphere of exoplanets.
Artistic impression of various planetary systems, with stars of different sizes and different orbital configurations.Source: Wikipedia
It’s not every day that we can see the birth of a star and its planets, but with the JWST this will become more frequent as the telescope will be able to see through the dust clouds surrounding the birth of planetary systems, enabling direct imaging of the moment the star forms.
Furthermore, with the resolving power of the new telescope, it will be possible to study in detail the atmosphere of other planets. These new observations will allow us to understand which chemical elements are present on other planets and will facilitate the finding of biosignatures.
Biosignatures are traces of chemical elements related to the presence of life on the planet. The existence of life on Earth fundamentally altered our planet’s atmosphere, creating a large presence of oxygen, for example. We expect the same when studying other planets, and the JWST will allow for great advancement in this area.
Illustration of how the study of spectroscopy works when detecting an element present in an atmosphereSource: NASA
The detection of biosignatures for the first time could represent the discovery of life beyond Earth!
We’ll also look closer: our own Solar System. The JWST will allow a more detailed study of planets like Mars, the gas giants, and even smaller elements of the Solar System, like Pluto, Eris and small bodies. Observations of the atmosphere of Mars will help you understand its organic traits and history. On the other hand, we will be able to understand the meteorology of Saturn and Jupiter, building our understanding of the seasonal climate of these gas giants.
These are some of the discoveries that will be possible with the long-awaited launch of the James Webb Space Telescope. Furthermore, there are all possibilities of the unknown.
What will the future post James Webb Space Telescope bring us?
Camila de Sá Freitas, columnist of TechWorld, holds a bachelor’s and master’s degree in astronomy. She is currently a PhD student at the European Southern Observatory (Germany). Self-styled Galaxy Examiner, he investigates evolutionary scenarios for galaxies and possible changes in star-making. It is present on social networks as @astronomacamila