New research suggests that water may have formed in the universe much earlier than previously thought. Scientists now believe that water molecules could have appeared just 100 to 200 million years after the Big Bang, billions of years before earlier estimates. This discovery challenges existing theories about the timeline of planetary and biological evolution, raising new questions about when and where life could have started.
A study published in Nature Astronomy suggests that early supernova explosions played a major role in water formation. Initially, the universe contained only basic elements like hydrogen, helium, and lithium. Oxygen, which is essential for water, was produced in the first-generation stars. When these stars exploded in powerful supernova events, they released oxygen into space, making it possible for water molecules to form.
Researchers examined two types of supernovas—core-collapse supernovas and pair-instability supernovas. These explosions generated dense gas clouds, where oxygen combined with hydrogen to create water. Although the amount of water was limited, it was concentrated in regions where stars and planets were likely to form. This suggests that galaxies emerging from these clouds may have contained water from their very beginning.
If confirmed through future observations, such as those using the James Webb Space Telescope, this breakthrough could transform our understanding of how early galaxies formed and when the conditions for life first appeared in the universe.