Arhat Ingle
James Webb Space Telescope or JWST was launched on December 25, 2021 from French Guiana aboard the Ariane 5 rocket after awaiting its launch from March due to the Covid pandemic. The space observatory is finally on its way to its destination. But why is it so famed and what future does it hold?
The JWST is referred to as the successor of the Hubble space telescope and is made for observing farther in space than ever before, search for the first stars and galaxies created after the Big Bang, better understand how planets, stars and galaxies are born and evolve over time, explore distant worlds and study our solar system, determine the potential for life on planets around other stars.
The Hubble gave us many spectacular marvels of the deep space. The farthest that Hubble has seen so far is about 10-15 billion light-years away. The new space telescope, the most expensive one yet, could look as far as 13.5 billion light-years and further.
The telescope is set on its path to its destination that is the solar orbit and it will be 1 million miles away from earth at what is called the second Lagrange point or L2. The journey alone takes about a month and the unfolding process will take place soon and take two weeks, tweeted NASA after the successful blastoff of the telescope. The Hubble is just 340 miles away. This gives the JWST more favourable conditions to operate its infrared instruments and cameras in dark and cold conditions which are very important for a space telescope and infrared instruments. This telescope, unlike Hubble, is hard to be accessed by humans for reparation and upgrades. JWST’s scientific operations are expected to begin in the summer of 2022 and will be managed by the Space Telescope Science Institute in Baltimore.
The telescope is the result of the joint efforts by NASA, European Space Agency, and the Canadian Space Agency. The telescope, development of which began in 1996, was named after James E. Webb who served a great deal in the Apollo missions. The telescope was set to launch in 2007 and had an initial budget of $500 million which rose to $10billion over time.
JWST has a unique open body structure and a very peculiar “unfolding method” like origami. It has a beryllium, gold coated mirror which is 6.5m across and it is made up of 18 smaller hexagonal mirror segments each measuring about 1.32m in diameter. The telescope also has a secondary mirror that is 0.74m in diameter. In order to protect it from solar heat and light, it has a five-layer sun shield that expands in all directions. When deployed each layer is almost equivalent to the size of a tennis court. The shield is made up of Kapton covered with aluminium for reflectivity. The shield keeps the telescope cool helping it capture infrared light from distant stars and galaxies. JWST will use infrared light, which cannot be perceived by the human eye, to study every phase in cosmic history. The telescope's four scientific instruments are specifically designed to capture infrared light, and will be able to peer through cosmic dust to study colder or very distant objects.
The JWST with all these features would be able to give us better, more magnificent pictures of the universe and help us understand our origin and look at ‘toddler’ galaxies, stars formed just a while after The Big Bang, that is just a 100 billion years after the event. The telescope is also referred to as the ‘time machine of astronomers’ and has very high expectations just like its inspiration and predecessor The Hubble space telescope which didn’t disappoint.
(The writer is a student, St Joseph School, Jalgaon).