ORIGIN OF WATER IN UNIVERSE: GEOGRAPHY
NEWS: Search for universe’s first water could reset timeline of life’s origins
WHAT’S IN THE NEWS?
A recent study published in Nature Astronomy reveals that water formed in the early universe due to supernovae from Population III stars, challenging current theories. The research suggests that habitable planets could have emerged much earlier, potentially 100-200 million years after the Big Bang, pushing back the timeline for the potential origin of life.
Study on the Origin of Water in the Universe
Background
• Published In: The study was published in the journal Nature Astronomy.
• Conducted by: The research was conducted by the University of Portsmouth’s Institute of Cosmology and Gravitation, England.
• Methodology:
• The researchers ran 3D simulations using numerical experiments on Population III supernovae, the universe's oldest stars, composed entirely of hydrogen and helium.
• The simulations focused on how ionising UV radiation from these stars affects the ambient gas over their lifetimes, potentially leading to the formation of water.
Focus of the Study
• Supernovae Types: The study focused on two types of supernovae:
1. Core-Collapse Supernovae: Occurs when a massive star collapses under its own weight, triggering a massive explosion.
2. Pair-Instability Supernovae: Happens when a star’s inner pressure suddenly drops, causing the star to collapse.
Key Findings of the Study
1. Origin of Water in the Universe:
• The oldest stars of the universe, known as Population III stars, created conditions for water to form.
• As these stars reached the end of their lifecycles, they exploded in supernovae, dispersing elements like hydrogen, oxygen, and other elements.
• This dispersion helped oxygen and hydrogen to combine and form water molecules.
2. Timeline:
• The conditions for the creation of water likely existed between 50 million to 1 billion years after the Big Bang, coinciding with the period when the first supernovae occurred.
3. Stellar Remnants:
• The remnants of these massive Population III stars (after their explosion) left behind critical elements like hydrogen and oxygen, which were key for water formation.
• Oxygen formation occurred during the late stages of nuclear burning in massive stars that eventually exploded as supernovae.
4. Water Formation:
• The combination of oxygen and hydrogen in the intense heat and pressure of the supernova remnants allowed for the formation of water.
• The water molecules were highly concentrated in dense regions of gas, called cloud cores, which are considered to be the birthplaces of new stars and planets.
Significance of the Study
1. Water Modelling in the Primordial Universe:
• This is the first time that water has been modelled in the primordial universe, highlighting its formation in the early stages of cosmic evolution.
2. Implications for Planet Formation:
• The discovery suggests that habitable planets could have started forming much earlier than previously thought, potentially 100-200 million years after the Big Bang, before the first galaxies even existed.
3. Life Potential in the Early Universe:
• The findings extend the timeline for potential life to have emerged in the universe, pushing it back to a period much earlier than earlier models suggested.
4. Validation of Previous Research:
• The research validates previous studies that suggested some of Earth's water was delivered by comets during the early formation of the planet.
• It also affirms that water molecules in our solar system and on other planets likely remain unchanged from their interstellar origins, confirming their deep-rooted cosmic connections.
Conclusion
• The study not only challenges current theories about the origin of water in the universe but also offers new insights into the potential for life in the early universe, reinforcing the possibility of habitable planets existing much earlier than expected.
Source: https://www.thehindu.com/sci-tech/science/universe-water-origins-supernovae-reset-life-timeline/article69352989.ece