Portsmouth study finds first supernovae seeded planet building blocks 100 million years after Big Bang

August 13, 2026 at 02:20 AM2 min

This digest was compiled by AI from multiple sources — links to the originals are below.

University of Portsmouth researchers report that the first supernovae seeded the building blocks of rocky planets about 100 million years after the Big Bang, long before the first galaxies existed. Simulations show a disk around a young star 70% as massive as the sun accumulated several Earth masses of solid material and substantial water. The finding challenges earlier assumptions that planet formation began billions of years later.

Pop III Supernovae

The first stars in the universe ended as Pop III supernovae, scattering carbon, oxygen and iron into surrounding gas. A single pair-instability supernova can eject more than 100 times the sun's mass in heavy elements, according to the University of Portsmouth team. These explosions enriched nearby gas clouds to high concentrations of heavy elements, which then collapsed under gravity to form disks around young stars.

Planet-forming Disk

The simulation found a disk around a young star about 70% as massive as the sun. It accumulated enough solid material to create several Earth masses of planetary building blocks at roughly the same distance from the star as Earth is from the sun. The disk also contained substantial water, only a few times less than the amount available when the solar system formed, indicating any planets there could have received water in a way similar to Earth.

Cosmic Timeline

The results place planet-building conditions at 100 million years after the Big Bang, within a universe now about 13.8 billion years old. That is long before the first galaxies existed and contradicts previous assumptions that planet formation only gained pace several billion years into cosmic history. The study was led by Daniel Whalen of the University of Portsmouth's Institute of Cosmology and Gravitation, with PhD student Chris Jessop running the first part of the simulation chain.