The solar system is surrounded by a giant cloud of cometary nuclei, which is named after the Dutch scientist J. Oort, who proved its existence in 1950. Comets move in extremely elongated orbits and comets spend most of their period in the vicinity of their aphelions. The cloud boundaries are assumed at a distance of 20,000 – 200,000 AU. e. from the sun. In addition to this outer layer of comets, there is also an inner layer beyond Pluto’s orbit. Its inner border is located at a distance of no more than 2000 AU.
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.