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.
Biggest meteor craters on Earth. Vredefort, South Africa. Located at the south-west of Johannesburg, the crater is believed to have been made by an asteroid impact on Earth some two billion years ago. With an estimated radius of 118 miles (190 km), the crater is reportedly the site of the largest energy release in the world.