Mean surface level atmospheric density refers to the average density of an atmosphere at a planet's surface, which can be calculated using pressure, gravity, and height. For Mars, the relevant equation involves the relationship between pressure, density, and gravitational force. The discussion emphasizes the need for initial attempts at solving the problem before seeking further assistance. It suggests that assuming an ideal, monatomic gas may be a necessary consideration. Engaging with the problem is crucial for receiving help in understanding the concept.