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What is Explosive Nucleosynthesis?

Explosive nucleosynthesis is a cosmic phenomenon where new elements are forged in the heart of cataclysmic events like supernovae. As stars explode, intense temperatures and pressures enable atoms to fuse, creating heavier elements that enrich the universe. This process is key to understanding how the elements on Earth and in our bodies came to be. Curious about the elements that make up your world? Keep reading to uncover the secrets of the stars.
Michael Anissimov
Michael Anissimov
Michael Anissimov
Michael Anissimov

Explosive nucleosynthesis is the creation of heavy elements which occurs in the heart of a supernova. A supernova is a hugely energetic astronomical event where a supergiant star depletes its nuclear fuel and collapses under its own gravity. The infalling matter bounces against a superdense core, creating an explosion and a shock front which travels away from the core at speeds of up to 2000 km/s. A supernova can outshine its host galaxy, and they have been observed by astronomers since ancient history.

Stars obtain their energy through the fusion of atomic nuclei, mainly hydrogen and helium. This is called hydrogen and helium burning. In very massive stars, the burning of these elements creates an "ash" of heavier and heavier elements — carbon, neon, silicon, iron, and nickel — until finally the amount of energy necessary to fuse nuclei exceeds the energy it releases, and the nuclear chain reaction is extinguished. What is left is an iron-nickel core consisting of approximately 1.38 solar masses, which then collapses quickly into either a neutron star or a black hole, causing a supernova from the bounceback. Another type of supernova, called a Type Ia supernova, occurs in less massive stars. A Type Ia supernova occurs when a carbon-oxygen white dwarf exceeds the same 1.38 solar mass threshold and burns all of its contents in a matter of seconds.

The universe expanded rapidly immediately following the Big Bang.
The universe expanded rapidly immediately following the Big Bang.

In both types of supernova, temperatures in the billions of degrees are created at the core, and several solar masses of material is ejected outwards at 3% of the speed of light. Even though fusing together iron and nickel nuclei is very costly in terms of energy, a supernova is more than enough to initiate the necessary reactions. Every element heavier than iron on the Periodic Table is either created in supernovae explosions or is a decay product of those elements.

Explosive nucleosynthesis occurs in the heart of a supernova.
Explosive nucleosynthesis occurs in the heart of a supernova.

Supernova nucleosynthesis is only one category of nucleosynthesis. The more typical type of nucleosynthesis is stellar nucleosynthesis, primarily of the hydrogen and helium burning type mentioned before. There is also Big Bang nucleosynthesis, which occurred during the first three minutes of the universe's existence. During this event, 24% of the initial hydrogen atoms in the cosmos were fused into helium nuclei. Currently, the observable universe is made up of about 74% hydrogen, 24% helium, 1% oxygen, and 1% other elements.

Michael Anissimov
Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

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Michael Anissimov
Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

Learn more...

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    • The universe expanded rapidly immediately following the Big Bang.
      By: 123dartist
      The universe expanded rapidly immediately following the Big Bang.
    • Explosive nucleosynthesis occurs in the heart of a supernova.
      By: satori
      Explosive nucleosynthesis occurs in the heart of a supernova.
    • The periodic table is a table of the chemical elements in which the elements are arranged by order of atomic number.
      By: jelena zaric
      The periodic table is a table of the chemical elements in which the elements are arranged by order of atomic number.