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.
Also the second largest impact structure on Earth, the 1.85 billion years old Sudbury crater in Canada, hosts world-class mineral deposits - in this case nickel-rich minerals that were melted and concentrated by the extreme heating caused by the impact.
The 40 mile (64.3 km) wide crater is linked to the nearby Ust-Kara crater and many claim that the two were formed by a single impact, in which case they would form one of the largest craters on earth at 74.5 miles (120km). (Pictured) Satellite image of the crater taken on Sept. 27, 1992.