Astronomers calculate that the essential chemical ingredients for rocky planets formed just 100 million years after the Big Bang, far earlier than previously assumed. Computer simulations by University of Portsmouth researchers show that monstrous Population III stars seeded early cosmic gas clouds with heavy elements via violent pair instability supernovas.
Conventional astronomical theory long held that planet formation was a late-stage development in cosmic history. Researchers typically assumed that building blocks like carbon, oxygen, and iron only accumulated in meaningful quantities once the universe matured and cycled through multiple generations of sun-like stars. A new computer simulation project led by researchers at the University of Portsmouth challenges that timeline entirely, pushing the dawn of planetary chemistry back to roughly 100 million years after the Big Bang.
Given that the universe spans approximately 13.8 billion years, discovering planetary ingredients at that early stage is the equivalent of building the first house on a street before the surrounding town even exists. This profound shift in the cosmic timeline opens intriguing possibilities regarding how early habitable worlds could have emerged before the Milky Way ever formed.
Supernovas and Population III Stars as Cosmic Forges
The timeline rewrite begins with the universe’s inaugural stellar generation, known as Population III stars. These bodies were monstrous by modern standards, and some ended their short lives in a pair instability supernova. Physics permits few events more violent than these explosions, which can hurl more than a hundred times the Sun’s mass in heavy elements out into empty space.
Dr. Daniel Whalen and PhD student Chris Jessop led computer simulations to trace the trajectory of that scattered debris. Their models revealed that the blast fallout could enrich nearby gas clouds so densely that the material collapsed under its own gravity. The clouds spun up into dense discs around newly forming stars, bearing a striking resemblance to the protoplanetary disc that once surrounded our infant Sun.
Solid Material and Water in Early Protoplanetary Discs
Within one specific simulation run by the Portsmouth team, a disc formed around a star possessing roughly 70 per cent of the Sun’s mass. Hidden inside that swirling structure, the researchers identified several Earth masses’ worth of solid material situated roughly where our home planet orbits today, one Sun-Earth distance out.
An even larger surprise emerged regarding water content. The disc held a healthy supply of water, coming remarkably close to the volume available when our own Solar System coalesced. Because scientists believe water delivery via ancient discs drives how worlds like Earth acquire their oceans, finding it in early systems completely reframes expectations.
Implications for Early Habitable Worlds
These computational models demonstrate that the chemical scaffolding required to build rocky worlds existed almost from the beginning of cosmic time. While astronomers cannot yet confirm whether life actually took root in those primitive systems, the work confirms that the raw materials were ready far sooner than anyone previously dared to imagine.
As the researchers note, discovering that planetary ingredients were in place during the universe’s infancy raises a compelling question: could habitable worlds have formed long before there was a Milky Way to call home? Future observations must determine just how widespread these early discs were and whether any ancient worlds managed to secure a head start on the rest of the cosmos.
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