Close Menu
TechCentralTechCentral

    Subscribe to the newsletter

    Get the best South African technology news and analysis delivered to your e-mail inbox every morning.

    Facebook X (Twitter) YouTube LinkedIn
    WhatsApp Facebook X (Twitter) LinkedIn YouTube
    TechCentralTechCentral
    • News

      Public money, private plans: MPs demand Post Office transparency

      13 June 2025

      Coal to cash: South Africa gets major boost for energy shift

      13 June 2025

      China is behind in AI chips – but for how much longer?

      13 June 2025

      Singapore soared – why can’t we? Lessons South Africa refuses to learn

      13 June 2025

      10 red flags for Apple investors

      13 June 2025
    • World

      Yahoo tries to make its mail service relevant again

      13 June 2025

      Qualcomm shows off new chip for AI smart glasses

      11 June 2025

      Trump tariffs to dim 2025 smartphone shipments

      4 June 2025

      Shrimp Jesus and the AI ad invasion

      4 June 2025

      Apple slams EU rules as ‘flawed and costly’ in major legal pushback

      2 June 2025
    • In-depth

      Grok promised bias-free chat. Then came the edits

      2 June 2025

      Digital fortress: We go inside JB5, Teraco’s giant new AI-ready data centre

      30 May 2025

      Sam Altman and Jony Ive’s big bet to out-Apple Apple

      22 May 2025

      South Africa unveils big state digital reform programme

      12 May 2025

      Is this the end of Google Search as we know it?

      12 May 2025
    • TCS

      TechCentral Nexus S0E1: Starlink, BEE and a new leader at Vodacom

      8 June 2025

      TCS+ | The future of mobile money, with MTN’s Kagiso Mothibi

      6 June 2025

      TCS+ | AI is more than hype: Workday execs unpack real human impact

      4 June 2025

      TCS | Sentiv, and the story behind the buyout of Altron Nexus

      3 June 2025

      TCS | Signal restored: Unpacking the Blue Label and Cell C turnaround

      28 May 2025
    • Opinion

      Beyond the box: why IT distribution depends on real partnerships

      2 June 2025

      South Africa’s next crisis? Being offline in an AI-driven world

      2 June 2025

      Digital giants boost South African news media – and get blamed for it

      29 May 2025

      Solar panic? The truth about SSEG, fines and municipal rules

      14 April 2025

      Data protection must be crypto industry’s top priority

      9 April 2025
    • Company Hubs
      • Africa Data Centres
      • AfriGIS
      • Altron Digital Business
      • Altron Document Solutions
      • Altron Group
      • Arctic Wolf
      • AvertITD
      • Braintree
      • CallMiner
      • CYBER1 Solutions
      • Digicloud Africa
      • Digimune
      • Domains.co.za
      • ESET
      • Euphoria Telecom
      • Incredible Business
      • iONLINE
      • Iris Network Systems
      • LSD Open
      • NEC XON
      • Network Platforms
      • Next DLP
      • Ovations
      • Paracon
      • Paratus
      • Q-KON
      • SkyWire
      • Solid8 Technologies
      • Telit Cinterion
      • Tenable
      • Vertiv
      • Videri Digital
      • Wipro
      • Workday
    • Sections
      • AI and machine learning
      • Banking
      • Broadcasting and Media
      • Cloud services
      • Contact centres and CX
      • Cryptocurrencies
      • Education and skills
      • Electronics and hardware
      • Energy and sustainability
      • Enterprise software
      • Fintech
      • Information security
      • Internet and connectivity
      • Internet of Things
      • Investment
      • IT services
      • Lifestyle
      • Motoring
      • Public sector
      • Retail and e-commerce
      • Science
      • SMEs and start-ups
      • Social media
      • Talent and leadership
      • Telecoms
    • Events
    • Advertise
    TechCentralTechCentral
    Home » In-depth » The most powerful space telescope ever built launches this December

    The most powerful space telescope ever built launches this December

    By The Conversation16 October 2021
    Twitter LinkedIn Facebook WhatsApp Email Telegram Copy Link
    News Alerts
    WhatsApp
    The James Webb Space Telescope was specifically designed to detect the oldest galaxies in the universe. Nasa/JPL-Caltech

     

    Some have called Nasa’s James Webb Space Telescope the “telescope that ate astronomy”. It is the most powerful space telescope ever built and a complex piece of mechanical origami that has pushed the limits of human engineering. On 18 December 2021, after years of delays and billions of dollars in cost overruns, the telescope is scheduled to launch into orbit and usher in the next era of astronomy.

    I’m an astronomer with a specialty in observational cosmology – I’ve been studying distant galaxies for 30 years. Some of the biggest unanswered questions about the universe relate to its early years just after the Big Bang. When did the first stars and galaxies form? Which came first, and why? I am incredibly excited that astronomers may soon uncover the story of how galaxies started because James Webb was built specifically to answer these very questions.

    The universe went through a period of time known as the Dark Ages before stars or galaxies emitted any light. Space Telescope Institute

    Excellent evidence shows that the universe started with an event called the Big Bang 13.8 billion years ago, which left it in an ultra-hot, ultra-dense state. The universe immediately began expanding after the Big Bang, cooling as it did so. One second after the Big Bang, the universe was a hundred trillion miles across with an average temperature of an incredible 10 billion C. Around 400 000 years after the Big Bang, the universe was 10 million light years across and the temperature had cooled to 3 000 C). If anyone had been there to see it at this point, the universe would have been glowing dull red like a giant heat lamp.

    Throughout this time, space was filled with a smooth soup of high-energy particles, radiation, hydrogen and helium. There was no structure. As the expanding universe became bigger and colder, the soup thinned out and everything faded to black. This was the start of what astronomers call the Dark Ages of the universe.

    The soup of the Dark Ages was not perfectly uniform and due to gravity, tiny areas of gas began to clump together and become denser. The smooth universe became lumpy, and these small clumps of denser gas were seeds for the eventual formation of stars, galaxies and everything else in the universe.

    Although there was nothing to see, the Dark Ages were an important phase in the evolution of the universe.

    Light from the early universe is in the infrared wavelength – meaning longer than red light – when it reaches Earth. Inductiveload/Nasa via Wikimedia Commons

    The Dark Ages ended when gravity formed the first stars and galaxies that eventually began to emit the first light. Although astronomers don’t know when first light happened, the best guess is that it was several hundred million years after the Big Bang. Astronomers also don’t know whether stars or galaxies formed first.

    Current theories based on how gravity forms structure in a universe dominated by dark matter suggest that small objects – like stars and star clusters – likely formed first and then later grew into dwarf galaxies and then larger galaxies like the Milky Way. These first stars in the universe were extreme objects compared to stars of today. They were a million times brighter but they lived very short lives. They burned hot and bright and when they died, they left behind black holes up to a hundred times the Sun’s mass, which might have acted as the seeds for galaxy formation.

    Astronomers would love to study this fascinating and important era of the universe, but detecting first light is incredibly challenging. Compared to massive, bright galaxies of today, the first objects were very small and due to the constant expansion of the universe, they’re now tens of billions of light years away from Earth. Also, the earliest stars were surrounded by gas left over from their formation and this gas acted like fog that absorbed most of the light. It took several hundred million years for radiation to blast away the fog. This early light is very faint by the time it gets to Earth.

    But this is not the only challenge.

    As the universe expands, it continuously stretches the wavelength of light travelling through it. This is called redshift because it shifts light of shorter wavelengths – like blue or white light – to longer wavelengths like red or infrared light. Though not a perfect analogy, it is similar to how when a car drives past you, the pitch of any sounds it is making drops noticeably.

    By the time light emitted by an early star or galaxy 13 billion years ago reaches any telescope on Earth, it has been stretched by a factor of 10 by the expansion of the universe. It arrives as infrared light, meaning it has a wavelength longer than that of red light. To see first light, you have to be looking for infrared light.

    Enter the James Webb Space Telescope.

    Telescopes are like time machines. If an object is 10 000 light years away, that means the light takes 10 000 years to reach Earth. So, the further out in space astronomers look, the further back in time we are looking.

    Engineers optimised James Webb for specifically detecting the faint infrared light of the earliest stars or galaxies. Compared to the Hubble Space Telescope, James Webb has a 15 times wider field of view on its camera, collects six times more light and its sensors are tuned to be most sensitive to infrared light.

    The strategy will be to stare deeply at one patch of sky for a long time, collecting as much light and information from the most distant and oldest galaxies as possible. With this data, it may be possible to answer when and how the Dark Ages ended, but there are many other important discoveries to be made. For example, unravelling this story may also help explain the nature of dark matter, the mysterious form of matter that makes up about 80% of the mass of the universe.

    James Webb is the most technically difficult mission Nasa has ever attempted. But I think the scientific questions it may help answer will be worth every ounce of effort. Astronomers are waiting excitedly for the data to start coming back sometime in 2022.The Conversation

    • Chris Impey is distinguished professor of astronomy, University of Arizona
    • This article is republished from The Conversation under a Creative Commons licence


    Chris Impey Hubble Space Telescope James Webb Space Telescope
    Subscribe to TechCentral Subscribe to TechCentral
    Share. Facebook Twitter LinkedIn WhatsApp Telegram Email Copy Link
    Previous ArticleMTN joins Telkom in suing Icasa over temporary spectrum
    Next Article Vodacom joins rivals MTN, Telkom in court action over spectrum

    Related Posts

    Gases linked to life found in atmosphere of alien planet

    17 April 2025

    Bookmarks | Big Tech to take arse-kissing to new heights

    7 November 2024

    Webb space telescope reveals rapid growth of primordial black hole

    6 November 2024
    Company News

    Huawei Watch Fit 4 Series: smarter sensors, sharper design, stronger performance

    13 June 2025

    Change Logic and BankservAfrica set new benchmark with PayShap roll-out

    13 June 2025

    SAPHILA 2025 – transcending with purpose, connection and AI-powered vision

    13 June 2025
    Opinion

    Beyond the box: why IT distribution depends on real partnerships

    2 June 2025

    South Africa’s next crisis? Being offline in an AI-driven world

    2 June 2025

    Digital giants boost South African news media – and get blamed for it

    29 May 2025

    Subscribe to Updates

    Get the best South African technology news and analysis delivered to your e-mail inbox every morning.

    © 2009 - 2025 NewsCentral Media

    Type above and press Enter to search. Press Esc to cancel.