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.
Ubehebe (pronounced you-bee-hee-bee) Craters, located about 150 miles northeast of Bakersfield in Death Valley National Park, consists of at least a dozen overlapping volcanic craters. The largest crater is about 800 m (0.5 mi) wide and 250 m (800 ft) deep.