Azra Hoosen | ah@radioislam.co.za
16 January 2025 | 13:15 CAT
3 min read

In just three years, the James Webb Space Telescope (JWST) has revolutionised our knowledge of the cosmos. At the forefront of interpreting these discoveries is Professor Karl Glazebrook, an ARC Laureate Fellow and Distinguished Professor at Swinburne University of Technology. Professor Glazebrook recently discussed how JWST’s findings are reshaping our understanding of galaxy formation, star creation, and even the potential for extraterrestrial life in an interview on Radio Islam International.

He explained that James Webb is a major advance on the Hubble Space Telescope. “It’s a bigger telescope, with a mirror three times the size of Hubble’s, gathering nine times as much light, making it more sensitive and capable of producing sharper images.”

One of JWST’s most notable advancements is its ability to observe in the infrared spectrum. “Hubble sees the same wavelength of light we see. James Webb is an infrared telescope, so it sees beyond the range we can see. This is crucial for studying the early universe because as we look back in time, the light we see is increasingly redshifted by the expansion of the universe,” he said.

Since its deployment, the JWST has unveiled surprising findings, including evidence of galaxy formation much earlier in cosmic history than anticipated. “Even in the first week of data, we found populations of early galaxies forming very early in cosmic time,” said Professor Glazebrook. He noted that massive galaxies and black holes were already present within the first billion years.

These findings challenge existing cosmological models.“Our models, based on dark matter, predict a certain way galaxies grow. But James Webb is pushing the boundaries of that model. We’re finding massive galaxies earlier than expected, which strains these models. We may need to revise our understanding of how dark matter interacts with atoms or how gravity shapes galaxies in the early universe,” he explained.

Little red dots and the evolution of galaxies

One of the more intriguing discoveries is the so-called “little red dots” in the early universe. “These are compact objects that appear to be active galactic nuclei—galaxies with monstrous black holes at their centers, emitting vast amounts of radiation,” Professor Glazebrook explained. “There are likely 100 times more of these than we expected.”

The JWST has also provided unprecedented insight into star formation and the chemical composition of the early universe. “It has the ability to dissect light from distant objects to reveal the chemical fingerprints of elements. We think we’ve seen signatures of the first stars, which were composed almost entirely of hydrogen and helium,” he said.

Implications for life beyond earth

In addition to exploring the distant past, the JWST is studying planets closer to home, searching for signs of life. “James Webb can identify chemical signatures like methane or water in the atmospheres of planets,” Professor Glazebrook shared. “In the future, we might even detect biosignatures, like compounds produced by plants, though we haven’t seen anything like that yet,” he added.

Reshaping cosmology

As the JWST continues to deliver data, scientists are grappling with how its findings reshape our understanding of the cosmos. He stated that the rapid formation of massive galaxies, the presence of active black holes, and the discovery of dead galaxies early in cosmic time all point to interconnected phenomena.

When asked about the future, he expressed excitement: “Personally, I’d like to solve the problem of massive galaxies forming very early. We don’t know if this requires small adjustments or major revisions to our models. But JWST is providing exquisite data, and as a community, we are slowly piecing together the puzzle.”

A Glimpse of the Future

The JWST has only scratched the surface of its potential. From colliding galaxies to the search for life on distant planets, its discoveries promise to deepen our understanding of the universe. “The data quality is like the difference between night and day. Every time we get new images or spectra, it’s incredibly exciting. There’s so much to explore, and the future of cosmic exploration has never looked brighter,” said Professor Glazebrook.

As the telescope continues to unveil the mysteries of the cosmos, one thing is clear: the universe holds far more surprises than we ever imagined.

LISTEN to the full interview with Muallimah Annisa Essack and Professor Karl Glazebrook, here.