Comets belong to the small bodies of the solar system. The comet’s solid nucleus has a diameter of about 1-10 km. However, the gas-dusty atmosphere surrounding the core, when the comet approaches the Sun, forms a head, the diameter of which is comparable to that of the Sun (1.4 * 10 ^ 6 km). A comet’s tail can be as long as one astronomical unit or even more.
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.