The universe is an enigma, and every day we are making strides in our mission to unravel its mysteries. A significant step in this journey is the recent release of images and science data from various sky regions by the National Aeronautics and Space Administration’s (NASA) James Webb Space Telescope (JWST). This article will delve into the details of these discoveries, the objectives of the JWST, its comparison with the Hubble Telescope, and some other notable space missions.
About the James Webb Space Telescope
Launched as a multinational project by NASA, the European Space Agency (ESA), and the Canadian Space Agency in December 2021, the JWST has become a beacon of hope for cosmic historians. Positioned at the Sun-Earth L2 Lagrange point approximately 1.5 million km beyond Earth’s orbit, JWST is the most potent infrared space telescope ever built.
The telescope provides unparalleled insight into the early universe, enabling us to observe galaxies that appeared about 4.6 billion years ago. Its highly sophisticated infrared imaging capabilities allow scientists to study these ancient galaxies’ mass, age, history, and composition in detail.
The Objectives of JWST
The primary goal of JWST is to unravel the cosmos’ evolution, from the Big Bang to the formation of galaxies, stars, planets, and our solar system. This objective is broadly divided into four themes:
– Observing the first stars and galaxies that formed around 13.5 billion years ago.
– Comparing early, faint galaxies with today’s grand spirals to understand galaxy assembly over billions of years.
– Studying where stars and planetary systems are being born.
– Observing the atmospheres of extrasolar planets (those beyond our solar system) to potentially discover life’s building blocks in the universe.
How Does JWST Differ From Hubble?
While both telescopes have significantly contributed to space exploration, they differ in several key aspects. The JWST primarily observes infrared radiations from 0.6 to 28 microns, whereas the Hubble Telescope was tasked with observing the ultraviolet and visible light spectrum, covering a range of 0.8 to 2.5 microns.
Another distinction lies in their orbits. While Hubble orbits Earth at an altitude of 575 kilometres, JWST orbits the sun approximately 1.5 million kilometers away from Earth.
Lastly, although both can observe young galaxies, JWST’s near and mid-infrared instruments are uniquely equipped to study the earliest-formed galaxies and exoplanets.
Other Notable Space Exploration Missions
Besides the JWST, a number of other missions have also advanced our understanding of the universe. These include the Pioneer mission, which introduced us to gas giants like Jupiter and Saturn; Voyager probes 1 and 2, which provided discoveries about the same planets and their moons; Chandra X-ray Observatory, which has been exploring the most distant and peculiar astronomical phenomena in X-ray light since 1999; and the SPHEREx mission, set for launch in 2024 to survey the sky in optical and near-infrared light.
Brushing Up: A Previous UPSC Civil Services Examination Question
In the 2012 UPSC Civil Services Examination, a question asked what scientists cite as evidence for the continued expansion of the universe. Here’s the question and its solution:
“Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of the universe? Detection of microwaves in space, Observation of redshift phenomenon in space, Movement of asteroids in space, Occurrence of supernova explosions in space. Select the correct answer using the codes given below: (a) 1 and 2 (b) 2 only (c) 1, 3 and 4 (d) None of the above can be cited as evidence.”
The correct answer was (a). Both the detection of mysterious microwaves coming uniformly from all directions and the redshift of distant galaxies – both increasing linearly with their relative distance – serve as compelling evidence for our universe’s continued expansion.
The universe continues to inspire and intrigue us, and telescopes like the James Webb Space Telescope are critical tools to discover its fascinating secrets. Whether it’s looking at the most distant galaxies or exploring gas giants’ realms, these missions remind us that we are but a small part of a grand cosmic story.