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.
1. Vredefort. The Vredefort crater was formed over 2 billion years ago, 60 miles from Johannesburg, South Africa. The diameter of the crater is believed to have been approximately 185 miles across but has since greatly eroded. It is the oldest and largest impact crater ever formed on Earth. In 2005, the crater became an UNESCO World Heritage Site because of its geological significance.