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 research is published in Tectonophysics. The previous record holder was the Vredefort crater in South Africa, clocking in at a diameter of 380 kilometers (236 miles.) The Vredefort impact structure remains the oldest known crater in the world, forming about 2,023 million years ago.