What conclusion about the main property of matter can be reached by contemplating the starry sky?

The fact of the existence of celestial bodies unambiguously implies a conclusion about their motion. Systems consisting of stationary space bodies cannot exist under conditions of gravitational forces.

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.