Why do comets have no tails at great distances from the sun?

The comet’s nucleus is composed of ice, frozen gases, dust and metal particles. Only when approaching the Sun, the comet nucleus heats up, gases and dust are released from it, which form the comet’s tail.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.