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.
The Milky Way Galaxy is our home Galaxy. It is a spiral shaped galaxy, so large that it takes light nearly 100,000 years to cross it, at a speed of 186,000 miles per second! Our Sun is one of nearly 100,000,000,000 stars, meaning that our solar system may make up 0.0000000001% of the galaxy. We lie roughly 25,000 light years from the center and are neighbored by 3 galaxies, most notably, Andromeda.