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.
The crater has been named the Barringer Crater in honor of Daniel Barringer, who was first to suggest that it was produced by meteorite impact. It is also referred to simply as Meteor Crater. The crater is located approximately 69 km east of Flagstaff, near Winslow in the northern Arizona desert of the United States. It is the largest impact crater yet discovered in the United States, and one of the best preserved on earth.