Parts of the solar atmosphere include the photosphere , chromosphere , and the corona . The apparent edge of the Sun as it is seen in the sky. The region over the South Atlantic Ocean where the lower Van Allen belt of energetic, electrically charged particles is particularly close to the Earth's surface. The excess energy in the particles presents a problem for satellites in orbit around the Earth. Spectral Line A line in a spectrum due to the emission or absorption of electromagnetic radiation at a discrete wavelength .
Spectral lines result from discrete changes in the energy of an atom or molecule.
Different atoms or molecules can be identified by the unique sequence of spectral lines associated with them. Spectrometer An instrument for measuring the intensity of radiation as a function of wavelength . See Spectrograph . Spectrum Electromagnetic radiation arranged in order of wavelength . A rainbow is a natural spectrum of visible light from the Sun.