James Webb telescope: Light on dark matter

Source: The post is based on an article “James Webb telescope: Light on dark matter” published in the Indian Express on 29^th August 2022.

Syllabus: GS 3: Awareness in the fields of Space.

Relevance: Space Exploration of James Webb Space Telescope(JWST)

News: In 2021, the James Webb Space Telescope was commissioned into space to probe the universe. It has replaced the Hubble Space Telescope.

About the James Webb Space Telescope

What are the previous findings on space science?

In 1543, the Polish astronomer Nicolaus Copernicus professed that the Earth is not at the centre of the universe. Earth is just another planet revolving around the Sun. Although, at present, the broad contours of the universe are fairly well established, but details are still missing:

(a) At the “beginning” of time, all the energy was concentrated in a primeval fireball of extremely high temperature and density.

(b) Thereafter, the universe started expanding, due to a massive explosion, which is termed the Big Bang about 14 billion years ago.

(3) In the last few decades, it has been established that most of the universe is a combination of a mysterious kind of matter called dark matter and an even more mysterious unknown substance called dark energy.

What is the importance of the James Webb Space Telescope (JWST)?

It provides a unique opportunity to fill the gaps in knowledge with the help of understanding the electromagnetic radiation waves, emitted from cosmic objects.

Due to the expansion of the universe, electromagnetic radiation waves are stretched. In other words, visible light could be stretched into the longer infrared part of the spectrum. The JWST will study this Infrared radiation. Further, these radiations have the advantage of passing through dust clouds more easily than visible light.

The JWST will give an insight into how the first stars and galaxies formed from the primaeval soup of matter and radiation.

It will also allow us to compare the earliest galaxies (those that are furthest) to those that we observe today in our own cosmic neighbourhood.

Since it operates in the infrared, it can see through the dust clouds that obscure regions where star and planet formation is taking place.

The Webb produces a huge amount of spectroscopic data which can help reveal the chemical composition of the region producing the radiation. Studying the chemical composition of exo-planets would also determine whether life as we know it is possible in these extra-terrestrial worlds.

What are some important JWST observations made so far?

In July, the JWST released its first images of galaxies that might date back to almost 13 billion years ago. For Example, the cosmic cliffs of the Carina nebula, the Cartwheel galaxy, and Stephan’s quintet.

It has also provided an analysis of the atmosphere and indicated the presence of water in a giant gas planet orbiting a star about a thousand light years away.

Over its lifetime, the JWST would provide us with a powerful window to help us understand the cosmos better and comprehensively.