The James Webb Space Telescope has made a remarkable discovery, with the number of bright galaxies at the edge of space-time found to be tens, hundreds, or even 1000 times greater than what astronomers previously predicted. This is based on the observations made by the telescope in its initial weeks of studying the sky. The discovery has left experts in the field surprised and shocked. Michael Boylan-Kolchin of the University of Texas, Austin says, “No one was expecting anything like this,” while Rachel Somerville of the Flatiron Institute comments, “Galaxies are exploding out of the woodwork.”
The current understanding of galaxy formation suggests that gas clouds should condense into stars and galaxies at a much slower rate than what is reflected in the photos of the early universe taken by the James Webb Space Telescope, which were taken less than 500 million years after the big bang. This means that galaxy formation models may need to be revised in light of this new information. Garth Illingworth of the University of California (UC), Santa Cruz believes that this finding is “way outside the box” of current predictions.
The James Webb Space Telescope was launched in June of this year and is operated by NASA with support from the Canadian and European space agencies. It is positioned 1.5 million kilometers away from Earth and has a mirror that is 6.5 meters in size and six times larger than the Hubble Space Telescope. The James Webb Space Telescope is more sensitive to distant sources of light, which are stretched to longer, redder wavelengths by cosmic expansion, due to its infrared capabilities.
In the early days of its operation, the James Webb Space Telescope discovered a candidate galaxy that would have been the most distant object ever observed if it had been visible when the universe was only 230 million years old or 1.7% of its present age. Further surveys have since revealed that this object is just one of many early galaxies that are much brighter than expected. However, some scientists are cautious and warn that the abundance of early galaxies may be a mirage. Michael Boylan-Kolchin questions whether the James Webb Space Telescope simply “lucked out” and gazed into a massive cluster of galaxies that was denser than the rest of the early universe. The question will be answered once the Cosmic Evolution Early Release Science (CEERS) Survey expands its scope later this year and results from additional comprehensive surveys become available.
These young galaxies have already been found by the scientific teams operating the James Webb Space Telescope, as reported in recent preprints. If the abundance of early galaxies is confirmed to be real, astronomers may have to fundamentally rethink our current understanding of galaxy formation or cosmology. Charlotte Mason of the Niels Bohr Institute explains that research using the Hubble Space Telescope has shown that star formation has been occurring at a consistent rate for up to 600 million years after the big bang. However, the data from the James Webb Space Telescope suggests that in earlier eras, star formation was happening at a far faster rate, so quickly that gas clouds were collapsing without any restraint from heat or supernovae. Tommaso Treu of the University of California, Los Angeles, who is in charge of the GLASS Webb survey, states that his team is observing these young galaxies “form stars like crazy” and that they look “like giant balls of star formation and nothing else.”
The James Webb Space Telescope is already breaking astronomical records and has the potential to make many more exciting discoveries in the future.
