* Hot gas: The high temperature of the gas causes the atoms within it to become excited. This means their electrons jump to higher energy levels.
* Excited atoms: When these excited electrons return to their ground state, they release energy in the form of photons (light).
* Specific wavelengths: The energy released corresponds to specific wavelengths of light, creating a unique pattern of bright lines.
Therefore, the spectrum of the Orion nebula shows bright lines against a dark background, characteristic of an emission spectrum.
