NASA’s James Webb Space Telescope: A giant leap for our Mankind

NASA’s James Webb Space Telescope (JWST) is by far the most advanced telescope ever made. The JWST is the successor of Hubble Telescope, the one that has served humanity by showing the spectacular images of space.

The James Webb Space Telescope will also provide some incredible and spectacular pictures of deep space, galaxies, stars, and planet formations.

Who Was James Webb?

NASA’s second administrator, James Edwin Webb, is best known for leading the Apollo mission, the first space program to send humans to the moon.

He also played an important role in the two manned space programs that followed Apollo, Mercury and Gemini. Although Webb eventually died in 1992 at the age of 85, he left behind a huge legacy that would be the telescope that bears his name.

“It is fitting that Hubble’s successor is named after James Webb. Thanks to his efforts, we were able to get our first glimpse of the dramatic landscape of space,” said former NASA director Sean O’Keeffe of the observatory’s name. “He took our country on the first voyage of exploration and made our dreams a reality.”

But it was not always its first name that was assigned to the telescope; the telescope was known before as the Next Generation Space Telescope.

Launch Vehicle, Date, place And Time

The JWST is an infrared space observatory that was launched on December 25, 2021 from ESA’s Kourou launch site in French Guiana at 7:20 a.m. EST (12:20 a.m. EST. GMT; 9:20 a.m. local time in Kourou), aboard an Arianespace Ariane 5 rocket.

Cost And Purpose Of James Webb Space Telescope

The James Webb Space Telescope is NASA’s largest and most powerful space telescope and its cost is around $ 10 billion.
It studies the universe and tells us the history of the universe, from the Big Bang to the formation of extraterrestrial planets and beyond. This is one of NASA’s finest observatories, a giant space device that includes the Hubble Space Telescope for a deeper view of the universe.

Place Of Observation

The James Webb Space Telescope took 30 days to travel nearly a million miles (1.5 million kilometers) to reach a Lagrange point that is a gravitationally stable location in space. The JWST reached L2, Earth’s second solar Lagrange point on January 24, 2022.

What Is Lagrange2 Point?

L2 is a point in near-Earth space that faces the sun. This orbit will make the telescope stay aligned with the Earth as it orbits the sun. It’s a place that has been used for several other space telescopes, like the Herschel Space Telescope and the Planck Space Observatory.

What Are The Goals Of JWST?

To Observe The First Light.

There were a lot of galaxies and black holes formed after the Big Bang. The universe has been constantly expanding since then. These objects are now the most distant objects from us and the universe and are expanding at the fastest rate. This means that the visible light emitted by these objects is redshifted and has a very long wavelength when received by Earth. Therefore, we have to observe infrared rays from a distance in order to detect them.

How Galaxies Have Formed?

The JWST will observe distant regions where new galaxies are just starting to form. Astronomers want to know how the different types of galaxies we see form (spirals, rods, loose clusters, etc.) and how differences in conditions early in their formation play a role in determining the final shape of galaxies.

How Did The Stars Formed?

Stars form in areas with high densities of dust and gas clouds. One of the main problems with trying to observe star formation is that the dust surrounding young stars is opaque in the visible spectrum. However, infrared radiation from newly formed stars has longer wavelengths and passes through dust, so observations in infrared light reveal what is going on inside the dust and gas clouds around the star.

To find Possible Life On Other Planets.

To find the origins of life in the Universe, scientists need to study planet formation and evolution, including the material around stars where planets form.

A key issue is to understand how the building blocks of planets are assembled. Scientists do not know if all planets in a planetary system form in place or travel inwards after forming in the outer reaches of the system. The sensitive instruments on JWST will be able to obtain infrared images of giant planets and planetary systems and measure their ages and masses.

In addition to studying planets outside our solar system, scientists want to learn more about our own home. Studying the chemical and physical history of the large and small objects that came together to form the Earth can help us understand how life evolved on Earth.

The JWST is powerful enough to identify and characterize comets and other icy objects in the farthest corners of our solar system, which could hold clues to Earth’s origins.

Instruments Used In The JWST

1). NIRCam- The Near-Infrared Camera (NIRCam) is Webb’s primary imager that will cover the infrared wavelength range 0.6 to 5 microns.

NIRCam will detect light from the earliest stars and galaxies in the process of formation, the population of stars in nearby galaxies, as well as young stars in the Milky Way and Kuiper Belt objects.

NIRCam is equipped with an instrument called coronagraphs that help astronomers to take pictures of very faint objects around a central bright object, like solar systems.

NIRCam’s coronagraph works by blocking a brighter object’s light, making it possible to view the dimmer object nearby just like shielding the sun from your eyes with an upraised hand can allow you to focus on the view in front of you. With the coronagraphs, astronomers hope to determine the characteristics of planets orbiting nearby stars.

2). NIRSpec- Near-infrared spectroscopy (NIRSpec) works in the wavelength range of 0.6-5 microns. Spectroscopy (the science of interpreting lines) is one of the most powerful tools for studying the universe.

A spectroscope (sometimes called a spectrometer) is used to separate light from an object into a spectrum. Analyzing the spectrum of an object reveals physical properties such as temperature, mass, and chemical composition.

Atoms and molecules within an object can actually engrave a line in their spectrum, uniquely identify each existing chemical element, and reveal a lot of information about the physical state within the object.

3). MIRI- The Mid-Infrared Instrument (MIRI) has both a camera and a spectroscope that allows us to see the light in the mid-infrared part of the electromagnetic spectrum at wavelengths longer than our eyes.

MIRI covers the wavelength range of 5 to 28 microns. Its sensitive detector allows us to see distant galaxies, newly formed stars and faint comets, and redshifted light of objects within the Kuiper belt.

MIRI’s cameras provide wide-field broadband imaging that continues Hubble’s admired astrophotography around the world.

The spectroscope enables medium resolution spectroscopy and provides new physical details of the distant objects it observes.

4). FGS/NIRISS- The Fine Guidance Sensor (FGS) allows Webb to accurately point and capture high-quality images.

The near-infrared imagers and slitless spectrometers included in FGS/NIRISS are used to investigate scientific tasks such as first light detection, exoplanet detection and characterization, and exoplanet transit spectroscopy.

The FGS/NIRISS is a dedicated instrument with a wavelength range of 0.8 to 5.0 µm and three main modes, each dedicated to a different wavelength range. FGS is a “guide” to help point the telescope.

Difference Between Hubble And JWST

JWST scientific goals were motivated by Hubble’s results. Hubble science has pushed us to longer wavelengths than we have already done with Hubble.

As the distant objects have a stronger redshift and their light is forced from the UV and optical ranges to the near infrared range. Therefore, infrared telescopes are needed to observe these distant objects (such as the first galaxies to form in space).

This is another reason why Webb is not replacing Hubble. Its abilities are not the same. Webb will study the universe primarily in infrared, while Hubble will mainly study the universe in optics and ultraviolet light (despite having some infrared capabilities).

Power Of Lens

Hubble can see the smallest and newest of all galaxies.NASA says Webb will also be able to see newborn galaxies. Webb’s near-infrared and mid-infrared instruments could help study the first formed galaxies and exoplanets.

Size Of The Mirrors

The James Webb telescope mirror has a standard diameter of 6.5 meters. Webb is holding a large backboard measuring about 22m and 12m, which is almost the size of a tennis court. While Hubble mirrors are less than 2.4 meters in diameter.

The Webb has a much larger mirror than the Hubble. This large light-gathering area means Webb can see a far more distant past than Hubble.

Webb will see the universe in infrared, and Hubble will study the universe in optics and ultraviolet. Webb has bigger mirrors than Hubble.


Hubble is in a very close orbit around the Earth,Hubble orbits the Earth at an altitude of 575 km away from Earth, and Webb is 1.5 million kilometers (km) from the second Lagrange point (L2).


The James Webb Space Telescope is equipped with four scientific instruments that observe mostly in the infrared and offers a range of 0.6 to 28 microns.

While the Hubble’s instruments see mainly the ultraviolet and visible parts of the spectrum. It could only observe in the small range of 0.8 to 2.5 microns in the infrared.


JWST is designed primarily for near infrared astronomy, but can also see orange and red visible light, as well as the mid infrared region, depending on the instrument. It can also detect objects that are 100 times fainter than Hubble, and objects much earlier in the universe’s history which is upto redshift z≈20 (about 180 million years cosmic time after the Big Bang) while Hubble is unable to see beyond the very early reionization at about z≈11.1 (about 400 million years of cosmic time).

The JWST will help us to unravel some of the mysteries of the universe and solve many queries about our existence and how this universe started. We can also look deep into space and find any possible life or possibility of life on any other planet.

Read: How does the James Webb space telescope work?

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