Osteopenia refers to bone density that is lower than normal peak density but not low enough to be classified as osteoporosis. Bone density is a measurement of how dense and strong the bones are. If your bone density is low compared to normal peak density, you are said to have osteopenia.steopenia refers to bone density that is lower than normal peak density but not low enough to be classified as osteoporosis. Bone density is a measurement of how dense and strong the bones are. If your bone density is low compared to normal peak density, you are said to have osteopenia.
The Milky Way is the second-largest galaxy in the Local Group, with its stellar disk approximately 100,000 ly (30 kpc) in diameter, and, on average, approximately 1,000 ly (0.3 kpc) thick.
Now that we've done that, we can plug in the actual numbers. 1  For the galaxy, 50,000 light-years / 72 million light-years = 0.00069. 2  For Pluto, 2400 km / 4675 million km = 0.00000051. 3  Take the ratio of those two and you'll see that the galaxy appears 1300 times bigger than Pluto.