Earth Science

Beyond the Solar System

Star Power

Study Tip
A thermonuclear bomb reacts in the same way that a star produces energy; think about how much energy is released in both cases.

Nuclear Fusion

  • Stars are made up of hydrogen and helium atoms, which are packed densely to start nuclear fusion reactions.
  • The most common nuclear fusion reaction is two hydrogen atoms combining into a helium atom, thus releasing energy.
  • In order to counter the force of gravity and prevent a star from collapsing within itself, the energy from a nuclear reaction pushes outwards towards the surface of the star.
Study Tip
A thermonuclear bomb reacts in the same way that a star produces energy; think about how much energy is released in both cases.
  • Because of the outward pull of energy, stars shine brightly, releasing energy in the form of electromagnetic radiation.  

Particle Accelerators

  • By propelling subatomic particles towards each other, we can generate a tremendous amount of energy and create new particles, thus simulating the nuclear reactions that happen in the cores of stars.
  • A particle accelerator is a device used to achieve nuclear fusion.
  • Because particle accelerators simulate nuclear fusion reactions, it gives scientists a better understanding of how the universe works.
  • Particle accelerators are often very large: The SLAC National Accelerator Lab in California is over 2 mi (3.2 km) long!
The sun
The sun that we see every day is constantly creating nuclear reactions.
A particle accelerator built by CERN
A particle accelerator built by CERN can create enough energy
to simulate the amount of energy in the universe before stars were even created!
Concept Check
  • How do stars obtain their energy?
  • What can we use particle accelerators for?