One of the five elements is Fire. Through Him, we reach things to the Sun too...both representing heat and flame. Offerings are made to the Fire that is lit in small pits.Worship of the Five elements are important for us.And so is worship of the planets. The herbs that are used to light the fire and keep it going are medicinal and they have been proved ( scientifically) to eliminate pollution in the air.They kill the bacteria . The smoke that arises from the fire here cures ailments too.Way back, when there was with tragedy in our country in an Industrial city when thousands died after a gas leak in a factory, in the homes which were having this Fire worship no one was affected . Yes, there are among us a few who have this done every day in their homes in a small way without the big pit. And they become immune to several health hazards. These families are called Agnihothris- Fire worshippers. Generally the Homam or Fire worship is done for the welfare of the world. Each time the Priest offers something to the flames, he says "Idham na mama.." in Sanskrit meaning "this is not for myself .." Yes it has no - it SHOULD have no, self interest:-)))There will be a lot of Fire Pits in the hall where they perform this.