Question: what is the difference between the highest and lowest points on earth in km?
Answer: The highest point, atop Mount Everest, is 29,029 feet (8.9 km) above sea level. The deepest point, the Mariana Trench in the western Pacific Ocean, is 35,814 feet below sea level (10.9 km). The thin atmosphere at the altitude of Everest's peak has only about a third of the pressure measured at sea level.