RS Puppis is a Cepheid variable star, which varies in brightness, producing a light echo. A light echo occurs when light reflects off of surrounding objects, which delays its arrival to the observer.
Arainbow is an optical and meteorogical phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured arc.
Plant leaves and dead organic matter are broken down by decomposers,to produce soil nutrients for plants. This is an important role decomposers play in the nutrient cycles.
