By Advika Gudi
On Christmas day 2021, NASA launched one of its finest projects yet; a telescope that will help us look back in time – the James Webb. Designed to build on the work done by Hubble, the Webb telescope has a large 6.5m mirror, allowing it to gather seven times as much light and information from outer space than the Hubble. The 10 billion dollar product involved collaboration from NASA, and the European and Canadian Space Agencies. Once launched, the telescope unfolds and each solar panel blooms like a flower in the murky lake of space. Not only is The engineering efficient, it is an elegant work of art.
After having unfolded on 8th January 2022, the telescope will now gather information on the birth of the first stars and galaxies after the Big Bang. It will also learn about the formation and evolution of extrasolar planets, and give us more information on the composition of distant galaxies.
By using infrared light, the telescope can look much closer to the beginning of time, to when stars and galaxies first formed and ended the dark age of the universe. Light travels at a finite speed, and so the telescope collects light that has travelled billions of light-years from stars and galaxies to reach us in the present. From the light information collected, we can work backwards to see what they looked like and how they first formed. Looking at the galaxies through infrared is advantageous in two ways: One, when light travels far, it stretches out and redshifts into infrared light which is invisible to the naked eye. The only way to observe star birth as they happened ages ago, is to look at them through infrared. Two, interstellar dust, which births stars, blocks visible light while infrared passes through. Using infrared light is key to see into the cloud cores where stars fuse.
The Webb telescope will identify exoplanets (a planet beyond our solar system) using the transit method. This method works by detecting light from distant stars. When a planet passes in front of a star, it blocks some of the light. this change is detected and analysed to find how many planets orbit that star.
It will also use spectroscopy to learn about its atmosphere. Spectroscopy is a method of collecting information on the absorption and reflection of light by elements \ to find out the composition of matter. Using this method, we can see how objects formed when the universe cooled after the Big Bang and we can better understand planetary formations, their evolution, and even rank their suitability as habitats. As If the telescope wasn’t already achieving enough, it can also study galaxies far back in time, even ones that may be dead by now. It compares them to current galaxies to understand how galaxies evolve and how elements heavier than hydrogen and helium first formed.
The most fascinating bit is that every element in the universe was produced in those first stars and galaxies. They created the building blocks of the universe and are consequently responsible for life on Earth. The research on exoplanets will reveal answers on extraterrestrial life, and what makes a planet habitable. As Carl Sagan said, “The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.” The research done by the James Webb telescope is crucial in explaining where we came from and who we are – and it all starts at the dawn of the universe.
