1 One of the adverse effects of smoking analogue cigarettes is the damage to the cilia. 2  Cilia are the small hair-like organelles which assist in reducing your risk of infections by pushing mucus out of your lungs. 3  The regenerative process your lungs undergo include the repair of the cilia.
Mars is approximately half the diameter of Earth, and its surface area is only slightly less than the total area of Earth's dry land. Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass, resulting in about 38% of Earth's surface gravity.
Planet Earth, which we humans and all currently-known forms of life call home, is the third planet from the Sun, and the largest of the terrestrial planets. With a mean radius of 6,371 km (3,958.8 miles), it is slightly larger than Venus (which has a radius of approx. 6,050 km), almost twice the size of Mars (~3,390 km), and almost three times the size of Mercury (~2,440 km). Basically, Earth is a pretty big world. But just how big if one were to measure it from end to end?