What is the James Webb Space Telescope? Here is everything you need to know about NASA's most powerful telescope

The Webb telescope has produced breathtaking images of distant galaxies in space. Here is everything you need to know about what the telescope is, what it does, and why it was made.
Written by Sabrina Ortiz, Editor
The Pillars of Creation- Webb

The Webb telescope captures images of the Pillars of Creation.

Credits: NASA, ESA, CSA, STScI; Joseph DePasquale (STScI), Anton M. Koekemoer (STScI), Alyssa Pagan (STScI)

What is the James Webb Space Telescope?

If you've recently stumbled upon breathtaking images of space, you have probably just seen the products of the James Webb Telescope's work. The James Webb Telescope, often just referred to as the Webb telescope or JWST, is an orbiting infrared observatory that was launched as part of an international program between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA) to complement and extend the discoveries of the Hubble Space Telescope. 

The telescope views the world at infrared wavelengths, allowing for a deeper look into space to see the earliest stars and galaxies in the universe that formed after the Big Bang. The infrared light also makes visible stars and planetary systems forming inside clouds of dust visible which would otherwise be opaque. The telescope will help scientists search for the first galaxies formed after the universe was created and study these galaxies' evolutions. 

When was the Webb telescope launched?

The Webb telescope was launched on December 25, 2021 from Arianespace's ELA-3 launch complex at a spaceport located near Kourou, French Guiana. The Webb telescope was launched on an Ariane 5 rocket: the launch vehicle and launch site were part of the European Space Agency's contribution to the mission. After launch, the telescope went on its 29-day, million-mile journey to the second Lagrange point. 

Where is the Webb telescope located?

The Webb telescope operates from space and orbits the Sun 1.5 million kilometers away from Earth, called the second Lagrange point. This is a major difference from the Hubble telescope which orbits the Earth in low-orbit. 

Lagrange points refer to positions in space where the gravitational forces of a two-body system, such as the Sun and Earth, produce enhanced regions of attraction and repulsion, according to NASA. There are five total Lagrange points that can be used by NASA as "parking spots" for spacecraft in space to remain in a fixed position with minimal fuel consumption. 

The L2 point is an ideal home for the Webb telescope because at that point a spacecraft is close enough to easily communicate with Earth, provides a clear view of deep space for Webb and can keep the Sun, Earth and Moon behind the telescope for solar power. 

Why is it called the James Webb Telescope?

NASA named the telescope after James E. Webb who led NASA from February 1961 to October 1968. NASA says Webb, "did more for science than perhaps any other government official". It was under Webb's direction that NASA was able to land the first man on the moon in the Apollo program. His tenure led to a decade of space and science research that still remains unparalleled today. 

Who operates the Webb telescope?

The Webb telescope is an international collaboration between NASA, ESA and CSA. NASA is responsible for the Webb mission overall. ESA is responsible for providing the Near Infrared Spectrograph, Mid-Infrared Instrument Optics Assembly, and the Ariane Launch Vehicle, according to NASA. Lastly, CSA is responsible for contributing the Fine Guidance Sensor/Near Infrared Imager and Slitless Spectrograph. 

How much does the telescope cost?

The Webb telescope was an expensive project, expected to cost NASA $9.7 billion over 24 years, according to reports. The actual spacecraft development cost approximately $8.8 billion and an additional $861 million is planned to support five years of operations.

How long will the Webb telescope be in orbit?

The Webb telescope was designed to operate for a minimum of five years. However, the goal is having the overall mission lifetime greater than 10 years

What is the difference between the Webb telescope and the Hubble telescope?

When it comes to images from space, the terms "Webb" and "Hubble" have become buzz words. Therefore, it can often be difficult to differentiate between the two. Despite both being telescopes in space, both have major differences. 

The biggest difference between Webb and Hubble is where they orbit. Webb does not orbit around the Earth, like the Hubble telescope does. Instead, Webb orbits the Sun, 1.5 million kilometers away from the Earth. 

The valuable aspect of this orbit is that it lets the telescope stay in line with the Earth as it moves around the Sun. This means that the Hubble telescope is in low-Earth orbit and the Webb telescope is not. 

Credit: NASA

Another major difference between the telescopes is the images they render. The Webb telescope focuses on infrared wavelength while the Hubble telescope specializes in ultra-violet wavelength. Observations of distant objects, such as the first galaxies formed in the Universe, require an infrared telescope. Webb can, therefore, see objects in way farther distances and see further back in time then Hubble (I know it sounds like time travel, but we will get back to that later). 

Credit: NASA/ESA/M. Livio & Hubble 20th Anniversary Team (STScI)

There are also a plethora of technical differences between both telescopes, such as build, materials, size, flight duration, etc. that I will not weigh you down with. Both the differences listed above are the most important ones in understanding their different functions. 

Image: GSFC

How does the Webb telescope take images?

The Webb telescope's primary imager is its Near Infrared Camera (NIRCam). The NIRCam can detect light from the earliest stars and galaxies. The NIRCam was built in a joint effort from the University of Arizona and Lockheed Martin.

When did the Webb telescope capture its first image?

The first images were delivered by the Webb telescope in July 2022. President Joe Biden unveiled the first image taken by the telescope on July 11 2022 at a White House event. At the time, the image was the deepest infrared image of the universe anyone had ever seen. The image showed galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago. The full suite of images was then shared later that week and showcased spectacular color imagery.

Image: NASA, ESA, CSA, and STScI

How can I view images captured by the Webb telescope?

NASA always shares its latest news through press releases on its site. However, if you want to stay up-to-date with the latest Webb news, your best bet is following is the telescope's very own Twitter account

What has the Webb telescope accomplished?

The Webb telescope has provided the deepest and sharpest images of the universe so far. Building the telescope was an ambitious endeavor but now that it has proven successful, its technology will be implemented in telescopes in the future. Most recently, the Webb telescope shared breathtaking images of the iconic Pillars of Creation.

SEE: NASA's Webb telescope takes dazzling images of the Pillars of Creation

Can the Webb Telescope actually look back in time?

Even though this sounds entirely too much like science fiction, it is true. By looking out into space, you are essentially looking back in time because light needs time to travel across the vast distances of space to reach Earth. Light waves are always moving at extremely fast rates, about 186,000 miles per second, but that the light seen by the Webb may have left its source thousands of years ago.


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