Produced by: Tarun Mishra
Astronomers found unexpectedly large and bright galaxies in the early universe using the James Webb Space Telescope (JWST), raising questions about our understanding of the Big Bang.
Credit: NASA
The Big Bang theory describes the universe's history, starting from a smaller, hotter, and denser state. This model has consistently explained various cosmological observations over time.
While the Big Bang theory cannot predict specific galaxy locations, it estimates the number of small, medium, and large galaxies at different universe ages. JWST was designed to observe early galactic evolution directly.
In 2022, astronomers reported galaxies with redshifts over 16, suggesting they existed just 200-250 million years after the Big Bang. These galaxies appeared too large and fully formed for their age.
Initial headlines claimed these discoveries could challenge the Big Bang theory. However, these galaxies' redshifts were estimated using photometry, which is uncertain. Later, precise measurements revised their ages, aligning them with existing cosmological models.
New measurements confirmed the existence of galaxy JADES-GS-z14-0 with a redshift of 14.32, dating back to 290 million years after the Big Bang. This galaxy is small but bright, prompting further questions about early galaxy formation.
Credit: NASA
Possible explanations for these observations include early large black holes triggering star formation, supernova feedback enriching early galaxies with stars, or observational biases favoring small but bright galaxies.
While it's possible the Big Bang theory could be wrong, the current evidence strongly supports it. JWST is fulfilling its purpose by addressing significant questions about the universe's early stages.
Astronomers continue to investigate these early galaxies. Future observations and research may provide further insights, potentially requiring minor adjustments to cosmological models rather than upending the Big Bang theory.