Continuous positive airway pressure (CPAP) machines are used to maintain an open airway in patients diagnosed with obstructive sleep apnea. The machine functions by blowing pressurized air into the airway via mask at a setting determined by sleep study and prescribed by a physician.
Only around 180 impact craters have ever been discovered on Earth and around 30 per cent of them contain important natural resources of minerals or oil and gas. The largest and oldest known crater prior to this study, the 300 kilometre wide Vredefort crater in South Africa, is 2 billion years in age and heavily eroded.
U.S. Route 13 to S.R. 184. The Chesapeake Bay impact crater was formed by a bolide that impacted the eastern shore of North America about 35.5 Â± 0.3 million years ago, in the late Eocene epoch. It is one of the best-preserved wet-target or marine impact craters, and the largest known impact crater in the U.S.