Water, a fundamental ingredient for life, may have appeared far earlier in the universe than previously thought. New research suggests that water molecules could have formed as soon as 100–200 million years after the Big Bang, reshaping our understanding of the early cosmos.

How Water Forms In Space?

Water consists of hydrogen and oxygen, two elements that did not emerge at the same time. Hydrogen was one of the first elements to form after the Big Bang, alongside helium and lithium. These light elements played a crucial role in the birth of the first stars and galaxies.

Oxygen, however, did not exist at the beginning. It was produced much later inside massive stars through nuclear fusion. When these stars exploded in supernovae, they scattered oxygen and other heavier elements into space. This process set the stage for water formation, but until now, scientists were unsure how soon it could have happened.

New Research Suggests An Earlier Timeline

A study led by Daniel Whalen from Portsmouth University, published in Nature Astronomy, examined how water may have emerged in the aftermath of early supernova explosions. The researchers used computer simulations to study two supernovae:

• One from a star 13 times the mass of the Sun
• One from a much larger star, 200 times the Sun’s mass

Their results showed that these early explosions generated significant amounts of oxygen, which then combined with hydrogen already present in space. As these elements cooled and mixed, they began forming water molecules much earlier than expected.

Water Forming Faster Than Imagined

The simulations revealed that the smaller supernova produced a tiny but measurable amount of water within 30 to 90 million years after its explosion. In contrast, the larger supernova led to much faster water formation, with measurable amounts appearing in just 3 million years.

This suggests that water existed in space billions of years before Earth even formed. If this water could survive the violent processes of galaxy formation, it might have been incorporated into the earliest planetary systems.

Could Water Have Shaped Early Planets?

One of the most significant questions is whether this early water persisted or was destroyed by the extreme conditions of the young universe. The formation of the first galaxies involved intense radiation and gravitational disturbances, which could have disrupted water molecules.

However, if water survived, it may have been present in the first planetary systems—raising the possibility that conditions for life existed much earlier than previously assumed. If true, this could reshape the way scientists think about the origins of habitable worlds beyond our own.

This breakthrough suggests that water molecules may have formed billions of years earlier than scientists expected. It also hints that the seeds of life—at least in terms of available water—might have existed much earlier in the history of the universe.