Date: 30/08/2022

Relevance: GS 3: Science and Technology- developments and their applications and effects in everyday life. Awareness in the fields of Space.

Key Phrases: James Webb telescope, gravitational wave detectors, Integrated Science Instrument Module (ISIM).

Context:

• The James Webb telescope has shared many wonders of the universe with us.
• It necessitates the discussion about the telescope and various opportunities that it has w.r.t. exploration of the universe.

Background

• From the hunter-gatherer to our own times, every culture has developed its own cosmology i.e. the system of beliefs or theories, which explain the origin and structure of the universe.
• To study the heavens, a variety of instruments have been used throughout history. From sundials and astrolabes to telescopes and now gravitational wave detectors, we have tried to observe, chart, study and measure the universe.
• These observations have led to the formulation of our theories of the universe.

Examples from the recent past

• Kepler’s observations of the planets provided the impetus to Newton to formulate his law of gravitation which still forms the basis of celestial mechanics.
• In the early 20th century, the observation of receding galaxies by Hubble led to the model of the expanding universe.
• The quest to probe the universe received a major impetus with the commissioning of the James Webb Space Telescope.

James Webb Space Telescope

• It is an international collaboration between NASA, European Space Agency (ESA), and the Canadian Space Agency.
• It will be situated near the second Lagrange point of the Earth-Sun system which is directly opposite the Sun.
• It will be able to look back over 13.5 billion years to see the first stars and galaxies of our early universe and work in the infrared spectrum, collecting infrared light from the object it is focused on.
• Costing around $10 billion, the telescope has taken more than three decades from planning to commission and is truly a symbol of humanity’s intellectual and creative potential.
• It was launched in 2021 and reached its final orbit at a distance of around 1.5 million km from the Earth in early 2022.
• It took the engineers and scientists another six months to ready the instruments before they could be used.
• Infrared light has longer wavelengths than visible light and would help it look farther back in time more effectively than other telescopes.
• It will also help scientists look into the atmosphere of stars, which is usually shrouded with dust and gas during formation.

The observatory has four major components :

1. The Integrated Science Instrument Module (ISIM) which houses four instruments to analyze the light that is captured by the optical telescope element has a 21 feet diameter gold-plated beryllium primary mirror made of 18 hexagonal mirrors.
2. A secondary mirror to guide the light collected by the primary mirror to the instruments.
3. A huge foldable sun shield to block the radiation from the Sun, Earth and the Moon since the instruments need to operate at a temperature of -220 degrees Celsius.
4. The spacecraft bus with all the equipment for the operation of the observatory.

Recently released images

• In July, it released its first images and they were truly breathtaking.
• The images of galaxies that might date back to almost 13 billion years ago, the cosmic cliffs of the Carina nebula, the Cartwheel galaxy, the Stephan’s quintet.
• Though the colors were artificial since the images were infrared images and not visible light.
• It also provided an analysis of the atmosphere of a giant gas planet orbiting a star about a thousand light years away. The analysis indicated the presence of water in the atmosphere.

Making of Universe

• Developments in all regions of the electromagnetic spectrum and not just the visible range, over the last century have allowed us to know with reasonable certainty a lot about our universe.
• We know that at the beginning of time, all the energy was concentrated in a primeval fireball of extremely high temperature and density.
• Then with a massive explosion, termed dramatically the Big Bang about 14 billion years ago, the universe began and has been expanding since.
• At some point, a couple of hundred million years later, the first stars started forming.

Opportunities of Webb Telescope

• Although the broad contours of the universe are fairly well established, the details are still missing. Thus, the Webb telescope offers a unique opportunity.
• Our window to the universe is electromagnetic radiation which spans a whole spectrum of wavelengths from the very long radio waves through visible light to the ultra-short gamma rays, traveling at the speed of light.
• The expansion of the universe also stretches the waves and so visible light could be stretched into the longer infrared part of the spectrum.
• Infrared radiation has the advantage that it passes through dust clouds more easily than visible light.
• The Webb has four instruments to observe and analyze infrared waves. This makes it singularly suitable to observe the light emitted from the earliest epochs of the universe.
• This will give us an insight into how the first stars and galaxies formed from the primeval soup of matter and radiation.
• Because it can peer so far into the past, it will also allow us to compare the earliest galaxies (those that are furthest) to those that we observe today in our own cosmic neighborhood.
• And since it operates in the infrared, it can see through the dust clouds that obscure regions where star and planet formation is taking place.
• Webb doesn’t just produce pretty pictures. It also produces a huge amount of spectroscopic data which reveals, among other things, the chemical composition of the region producing the radiation.
• Studying the chemical composition of exo-planets — the planets orbiting other stars — would determine whether life as we know it is possible on these extraterrestrial worlds.

Our achievements so far

• In the last few decades, it has been shown that the kind of matter that our world is made of — the stuff of our iPhones, our earth and even us, is a mere 3-4 percent of the overall matter and energy in the universe.
• The rest is some combination of a mysterious kind of matter called dark matter and an even more mysterious unknown substance called dark energy.
• Not only are we not at the center of the universe, we are not even made up of the kind of stuff that the universe is mostly made of.
• Any vestigial remnant of our species’ anthropic arrogance has been finally demolished by cosmology.
• The universe is vast and most of it is unknown. We hope that the Webb, over its lifetime, would provide us with a powerful window to help resolve some of the many mysteries of the cosmos and make it a little bit more comprehensible.

Source: The Indian Express

Mains Question:

Q. The James Webb Telescope would provide us with a powerful window to help resolve some of the many mysteries of the cosmos. Comment. [150 Words].