Plutonium-244 nucleus size and scale context

The plutonium-244 nucleus is the heavy atomic nucleus of a long-lived plutonium isotope, built from 94 protons and 150 neutrons. It was forged in rare neutron-rich explosions before the Solar System formed, and its 81.3-million-year half-life made it an important extinct radionuclide in early Solar System history. Read its scale context, comparisons, and journey links on the canonical object page.

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Between the smallest and the largest, perspective is everything.

About

Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.

Guides turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.

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Between the smallest and the largest, perspective is everything.

About

Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.

Guides turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.

Editorial

Solar System Planets From Electron to Atoms Stars To Scale Birth And Death Of Stars Black Holes To Scale

Views

Planets of the Solar System Stars of the Universe Black holes Subatomic scale

Return to Earth hello@scaleofspace.org

Particles

Proton

The proton is the positively charged particle that gives every atomic nucleus its identity. Less than 1% of a proton’s mass comes from the masses of its quarks; almost all of the rest comes from the energy of quarks and gluons bound by the strong force.

Scale fact8.4 × 10^-16 mdiameter

Object class: Baryon

Particles

Plutonium-244 nucleus

Scale fact~15 fmdiameter

Object class: Atomic nucleus
Composition: 94 protons, 150 neutrons

Atoms

Hydrogen atom

Hydrogen is the universe’s simplest and most common atom. Most hydrogen nuclei were forged in the first minutes after the Big Bang, and neutral hydrogen atoms emerged only after the universe cooled enough for electrons and protons to combine about 380,000 years later.

Scale fact100 pmdiameter

Object class: Atom
Composition: 1 proton, 1 electron