James Webb Space Telescope
Seeing into the (very, very) distant past. (The Bus 8.33)
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ORIGINALLY PUBLISHED (4.32) 11 January 2024
The Stop
Named for James Webb, the administrator of NASA during the Mercury, Gemini and Apollo space programmes from 1961-1968, the James Webb Space Telescope (JWST) is a joint project of NASA, the Canadian Space Agency and the European Space Agency. Launched on 5 December 2021, the satellite observatory - the successor to the Hubble Space Telescope (launched in 1990) - differs from its predecessor in that it primarily detects light in the infrared range in order to ‘observe sources such as the first galaxies and protostars that radiate at those wavelengths’. In another departure from previous space telescopes, the JWST does not orbit the Earth, but instead orbits the Sun at the second Lagrange point which is around 1.5 million kilometres (1 million miles) away from the Earth.1
The largest telescope ever sent into space, the JWST’s infrared technology enables it to detect light beyond the visible spectrum. As infrared light travels through dense gas clouds that block visible light, the telescope is able to reveal regions of the universe that have been previously hidden: ‘early galaxies, forming planets, brown dwarfs, and much more.’ An ‘innovative design’ was required to construct the JWST as infrared telescopes have two unique challenges: there must be a mirror large enough to capture the required amount of light, and it must be kept cold in order to keep ‘unwanted sources’ of infrared from interfering with the light that astronomers want to observe. The solution was a large segmented mirror composed of 18 segments covering 6.5 meters (21.3 feet) at the widest point and a series of tennis court-sized sunshields that protect it from stray heat and light from the Sun.2
The results produced by the JWST are astounding, revealing a wealth of details only possible through capturing infrared images. In combination with visible-light images produced by the Hubble Space Telescope, astronomers are able to calculate galaxy distances using the principle of redshift: light from distant galaxies has a longer wavelength and is thus red, while light from closer galaxies has a shorter wavelength and is thus blue. Previously, there had been debate over whether some galaxies appeared redder because they were ‘more distant’ or because they contained ‘copious amounts of dust’. With its infrared lenses, the JWST is able to clarify this point.
The photo above is a panchromatic view of galaxy cluster MACS0416, created by combining infrared observations from the JWST with visible-light observations from the Hubble Space Telescope. The image was made by colour-coding the shortest light wavelengths blue, the longest ones red and the intermediate ones green. The result is the revelation of a ‘vivid landscape of galaxies that could be described as one of the most colourful views of the universe ever created.’ But, even more remarkable, the JWST has enabled the distance of MACS0416 to be calculated at about 4.3 billion light-years from Earth, which means the image above was as the cluster appeared shortly after the formation of our solar system. A serious snapshot in time.
For a library of the images released so far, follow this link: JWST Images. Click on one you like for an enhanced view and then scroll down for more information.
The Detour
Today’s Detour is to The Spirit Triangles, a short (3:13) animated film by the Tawainese visual artist Shih-Yen Huang. Using stop-motion techniques, Huang creates a unique synaesthetic experience by syncing a triangle to music and ambient sounds to which it continues to multiply and interplay. Hypnotic.
The Recommendation
Today’s Recommendation is Brian Cox’s Wonders of the Universe (2011).3 A companion book to the BBC documentary series of the same name, this is a very clearly written, beautifully illustrated book that uses the laws of physics on earth to explain cosmology and the universe in a way accessible to a general reader.
From the publisher: Professor Brian Cox is back with another insightful and mind-blowing exploration of space. This time he shows us our universe as we've never seen it before.
13.7 billion years old. 93 billion light years wide. It contains over 100 billion galaxies, each containing hundreds of billions of stars. This infinite, vast and complex Universe has been the subject of human fascination and scientific exploration for thousands of years. The wonders of the Universe might seem alien to us and impossible to understand, but away from the telescopes, the labs and the white coats, Professor Brian Cox uses the evidence found in the natural world around us to explain its simple truths.
The same laws of light, gravity, time, matter and energy that govern us here on Earth are the same as those applied in the Universe. Using 3D CGI imagery, his expert knowledge and his infectious enthusiasm, Professor Cox shows us that if we can understand the impact of these governing laws on Earth it will bring us a step closer to an understanding of our Universe.
The Sounds
Today’s playlist is a selection of five tracks connected to today’s Stop because they're all related to space (in one way or another): ‘Astronomy Domine’ (Pink Floyd, 1967), ‘Moonage Daydream’ (David Bowie, 1972), ‘Space Truckin’’ (Deep Purple, 1972), ‘Space Cowboy’ (Steve Miller Band, 1969) and ‘Black Hole Sun’ (Soundgarden, 1994). Enjoy!
The Thought
Today’s Thought is from the French poet, dramatist and novelist, Victor Hugo (1802-1885):4
‘We see past time in a telescope and present time in a microscope. Hence the apparent enormities of the present.’
If you have a thought on this Thought - or any part of today’s issue - please leave a comment below:
And that’s the end of this Stop - I hope you enjoyed the diversion!
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Until the next Stop …
Lagrange points are ‘positions in space where the gravitational forces of a two-body system like the Sun and Earth produce enhanced regions of attraction and repulsion. These can be used by spacecraft as ‘parking spots’ in space to remain in a fixed position with minimal fuel consumption.’ I’ve been a fan of all things space (both scientific and science-fictive) since I was a child and was very excited to see the images captured by the JWST when they were released. And they did not disappoint. Sources for today’s Stop include Lagrange points (NASA), Webb Telescope, JWST (NASA) and JWST (Britannica).
The innovations and new technology required to produce the JWST is astounding. For a good run-down of this information, see this NASA-produced Fact Sheet: JWST Fact Sheet (NASA).
Brian Cox is Professor of Particle Physics at the University of Manchester and The Royal Society Professor for Public Engagement in Science. He is best known to the public for a series of popular science books and the presenter of science programmes, especially BBC Radio 4’s The Infinite Monkey Cage and the Wonders of... series. For more information, see: Prof. Brian Cox (Royal Society).
For more about Hugo, see: Victor Hugo (Britannica).
The infrared vs dust ambiguity was one of those methodological bottlenecks that held back so much astronomy research for decades. JWST essentially turned what used to be educated guesses about galaxy composition into direct observations. The redshift clarification capability alone has prboably rewritten a dozen textbook chapters on early universe formation.