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 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.