The JWST is designed as an upgradation to the Hubble Space Telescope, which has made a revolution in the area of astronomy with its unique images of the space since its launch in 1990. While Hubble focus on visible and ultraviolet light, JWST will observe mainly in the infrared range of the electromagnetic spectrum, which is very helpfull for studying the universe before, far off galaxies, and the stars and planets formation.
The telescope has been under development for over twenty years and has faced a number technical difficulties and delays. Its planned launch date of december 2007 had been pushed many times due to this difficulties and finally it launched in december 22, 2021 from the European Spaceport in French Guiana.
The JWST has a primary mirror that is 6.5 meters (21.3 feet) in diameter, which is more than two times of the size of Hubble’s primary mirror. It is made up of 18 hexagonal segments that can be separately adjusted to compensate for distortions and difficulties caused by changes in temperature and the pressure of launch and deployment. The mirror have a thin layer of coating which is golden which helps in reflection of infrared light more efficiently.
The sunshield built in the telescope is another important part that is aimed to protect the sensitive components from the heat and light effects of the Sun. The sunshield is built in five layers of a unique material called Kapton, which is very thin, thinner than a hair follicle but have the strength of the steel. When it is fully deployed, the sunshield will grow as a size of a tennis court.
JWST will be fixed at a special point in space called the second Lagrange point (L2), which is about 1.5 million kilometers (930,000 miles) from Earth on the opposite side of the Sun. This location helps to provide a stable surroundings for the telescope to function without being affected by the heat effects and light of the Earth and Moon. It also allows the telescope to have a consistent view of the sky without frequent adjustments and fix ups
JWST have four main scientific components with each of it have unique purposes
- The Near Infrared Camera (NIR Cam) is the primary imaging instrument for the telescope which will be helpful for the studies of oldest galaxies, the stars and planets formation and the properties of exoplanets.
- The Near Infrared Spectrograph (NIR Spec) will be used to study the features of galaxies and the interstellar medium.
- The Mid-Infrared Instrument (MIRI) is designed to observe the early universe, far off galaxies.
- The Fine Guidance Sensor/Near InfraRed Imager and Slit less Spectrograph (FGS/NIRISS) will be used for the precision in pointing and tracking of the telescope.
The JWST mission has several scientific objectives, including:
- Studying the evolution and formation of galaxies: By observing the earliest galaxies in the universe, JWST will provide valuable informations into how the galaxies had formed and evolved over time. It will be a great help for astronomers for a better understanding about the relationship between black holes and galaxies.
- Studying the formation of stars and planets: JWST will observe the formation of stars and planets in both our own galaxy and others. It will be quickly able to detect the heat and light emitted by newly formed stars and their surrounding protoplanetary disks, which will provide insights for astronomers about how planets forms and evolves.
- Characterizing exoplanets: JWST will clearly study the atmospheres of exoplanets to find their chemical composition and temperature, as well as their potential for their durability as well as habitability. This will help us better understand the diversification of planets in our galaxy and their potential for life support
- Observing the early universe: JWST will observe some of the earliest galaxies in the universe, which formed just a few hundred million years after the Big Bang. By studying these galaxies, astronomers hope to learn more about the formation of the first stars and galaxies, as well as the evolution of the universe over time.
- Studying the interstellar medium: JWST will observe the interstellar medium, which is the material between stars in our galaxy.