VISIBILITY/WIPERWhile driving at freeway speed in Oregon, with 85 degrees ambient temperature and A/C inside set to 74 degrees, our CX-9 sunroof exploded outward. The sound was close to a very loud pop, and not the sound of rock/debris impact. At the time of explosion, there were no vehicles nearby and no overpasses from which an object could have dropped. The vehicle had been washed the day before and there was no visible damage to the sunroof. At the time of explosion, the sunroof and interior cover were closed. Upon stopping the vehicle (within less than one mile) inspection showed that nearly no glass fell downward, and approximately 50% of the total sunroof area had blown upward and out of the vehicle. The remainder of the shattered glass was still contained within the frame, with the edges visibly curved upward as though the glass had been pulled away from the car. There were three people in the vehicle at the time (driver, front seat passenger, and middle row passenger behind the driver). The two passengers were asleep and woke abruptly thinking we had been hit by something, as the explosive bang was followed by the sound of air rushing past the hole. There was no sound of glass rattling in the area over the sunroof cover, which seems to indicate glass had not broken inward and then blew out before stopping. I (driver) kept the cover closed and promptly pulled off the freeway to assess damage. I was unable to visit a dealer for warranty assessment due to vacation travel. A phone call to my local dealer did indicate it should be covered under warranty but it has not been inspected, this has not yet been confirmed. I rarely open the sunroof cover and have only opened the sunroof itself 3-4 times since purchase two years prior (2020). I did open the sunroof to give my son fresh air on curvy roads approximately one hour prior. No injuries, but if the cover had been opened we may have had glass falling into the cabin. No other visible or audible warnings occurred.