The linear resolution of details on the surface of Mars through a telescope is about 500 km. How, with the help of ground-based telescopic observations, were Mars satellites with a characteristic size of only 20 km discovered?
The contrast of satellites illuminated by the sun against a dark sky background is significantly higher than the contrast of fine details on the surface of Mars.
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.