Why is it impossible for a map of the world to portray Earth as accurately as can be done with a globe? 2. Why are there so many types of map projections? 3. Briefly describe the four major families of map projections: cylindrical projections, planar projections, conic projections, and pseudocylindrical projections 4. Why is a Mercator projection useful as a navigation map? Why is it not ideal for use as a general-purpose classroom map