The interval between the coverings in the condition of the problem is less than the stellar orbital period of the Moon (27.3 days). Consequently, Mars at this time moved in the sky relative to the stars towards the Moon, from east to west. This could only be near the opposition of Mars, therefore, the phase of the moon was close to full.
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.