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 largest crater on the moon is on the side we cannot see, and is named the South Pole - Aitken Basin. It is 2240km in width, and 13 kms deep. This is also the largest known crater in our solar system. The largest crater visible to us is the Bailly crater, which is 26 000 square miles in size.