Asteroids, Meteors, & Comets
Coma - The roughly spherical cloud surrounding the nucleus. Composed of water vapor, carbon dioxide, ammonia, dust, and neutral gases.
Dust Trail - Composed of, shockingly enough, dust. Faces both away from the sun, as well as opposite of the comet's direction of travel, which gives it a curve.
Ion Trail - Composed of charged gas. Always faces away from the sun due to the energy the sun gives off.