James Webb Space Telescope: The science behind the shots
What did the universe look like 13 billion years ago?
A lot has happened in the field of astrophysics since the James Webb Space Telescope (JWST) was launched in December 2021. Within a mere thirty days, the telescope travelled 1.5 million miles to its permanent home at the gravitationally stable location known as L2 Lagrange Point.
From there, the telescope has since gathered the most advanced imaging of the distant universe we have ever seen. Joe Biden was in fact the first person, outside of the team at NASA, to view JWST’s first ‘deep field’ image - galaxy cluster SMACS 0723, revealing the faintest objects and galaxies observed by humankind:
How did the James Webb Space Telescope take these images?
Before we get into more exciting discoveries afforded by JWST, it’s important to break down just how these images are taken. An essential component of the telescope is its state-of-the-art infrared sensors. The telescope was designed to pick up on infrared light at a frequency of 0.6 (red light) to 28 microns (infrared).
Long Waveform Capabilities
Because of its long waveform capabilities, JWST is able to detect matter beyond the gas and dust which is usually obscured by visible light, instead unearthing glimpses of the first stars and galaxies since the beginning of time, otherwise termed ‘the end of dark ages’ following the Big Bang. Whilst Hubble utilises ultraviolet sensors to collect its data, JWST’s exceptional infrared imaging is able to detect electromagnetic radiation data from further than ever before.
Where is data from JWST sent to?
The sensors on JWST measure the infrared energy detected, and send the data back to Earth, or, more specifically, to NASA’s Mission Operation Centre in Baltimore, Maryland.
JWST's infrared eyes
JWST’s field of view is 15X that of the Hubble. The infrared eyes in space are able to take images due to the following bits of world-class tech:
A near-infrared camera, or NIRCam
A near-infrared spectrograph (NIRSpec) capable of observing 100 objects at once
A cryocooler to main temperature (–266˚C) so that other equipment is otherwise unaffected
Fine guidance system and wide-field imager installed with an exoplanet spectroscopy mode (capturing light coming from planets outside of our solar system)
What kinds of images have been gathered so far?
Alongside the aforementioned SMACS 0723, the telescope has developed astronomy’s understanding of various nebulas and exoplanets. For instance, the Carina Nebula, looking like some sort of celestial cliff face, has been all over the internet for the past month.
JWST was able to capture imaging of star nurseries previously unseen in visible light. Below is an exceptionally high-resolution shot of what NASA has nicknamed ‘Cosmic Cliffs’ - a breath-taking image of Carina Nebula:
The Southern Ring Nebula
Another exquisite image is of the Southern Ring Nebula, a planetary nebula showing how a star, similar to our sun, has died. It has evolved and shed over time creating bubbles of material - gases spreading elements out through the universe, as seen below:
This image is a side-by-side comparison of the nebula taken by Hubble, vs JWST, respectively. One day the matter expelled from this nebula may form a new star or planet, and NASA will be waiting in the wings to see if this comes to fruition.
Another exciting part of JWST is its potential to reveal deeper insights into the nature of exoplanets.
In 2013, Hubble managed to show that water existed on WASP-96b - the first evidence we had seen of water in an exoplanet's atmosphere in the history of astrophysics. This discovery has served as a catalyst for investigations into what hundreds of other exoplanets are made up of. With the unprecedented quality afforded by JWST, we're already building on the discoveries of Hubble.
The picture below is of Stephan’s Quintet, as captured by JWST - a galaxy group of five galaxies, some colliding. This image is the largest image JWST has taken to date and, according to NASA, it captures “about one-fifth of the Moon’s diameter. It contains over 150 million pixels and is constructed from almost 1,000 separate image files.”
The image of this galaxy cluster also reveals black hole outflows in a manner never seen before in this region of our universe (whilst black holes swallow matter in a disc-like fashion, small bits of matter escape vertically via an outflow). A cosmic dance that holds great promise for the future of space exploration.
The Cartwheel Galaxy
On August 2, NASA released another one of JWST’s spectacular images - The ‘Cartwheel Galaxy’ (approximately 500 million light-years away), as seen below:
This glorious kaleidoscopic scene is actually the result of two galaxies violently colliding. It is categorised as a ‘ring galaxy’, far rarer than spiral galaxies or the remaining two categories of core galaxy structures (referred to as peculiar and irregular).
New technology particular to JWST is able to unearth far more than ever seen before - previous attempts to capture Cartwheel Galaxy have been pretty fruitless, but thanks to the composite of data gathered by the telescope’s Near-Infrared Camera and Mid-Infrared Instrument previously obscured celestial bodies are now in clear view.
As the bright outer ring expands it collides with gas, leading to the formation of more stars amidst the dust. The central part of the disc marks the original collision with its immemorial, pearlescent glow.
What more can we expect to see coming from JWST?
The future of the star gazing revolution has much in store. Not only might JWST be able to reveal colliding galaxies, dying planets, and hellish planets (a world so close to its star that its temperature rocks up to over 1000 centigrade, at night raining down in streams of molten iron or led), the telescope may well unlock the keys to alien civilisations. J
JWST is designed specifically to detect infrared - the spectrum of light crucial to unearthing the secrets behind exoplanets. If we already know that water exists on exoplanets, such as the likes of WASP-96b, there is the potential for life forms to be growing in places outside of this blue dot we call home.
There are many ways to keep on top of JWST updates:
There is also excellent content on YouTube, such as Launch Pad Astronomy’s channel
Dr Becky's channel where she deep dives into the JWST
We certainly can’t make it all the way to the deepest corners of our universe, but we can take some pretty exceptional videography and photography in near space. If you want to promote your business, service, or conduct avionics and satellite testing with the aid of a company who loves to frequent the stratosphere, please don’t hesitate to get in touch today!