UFO sightings are on the rise, and the U.S. government said better reporting systems and "reduced stigma" are to blame.  
The Pentagon has now received 510 reports of unidentified flying objects, according to a report release Friday. Many of those reports, 366, were added to the total in just the last two years. The other 144 sightings were reported over a 17-year period. 
One reason for the uptick is the establishment in 2022 of the All-domain Anomaly Resolution Office, which was set up to analyze reports of unidentified phenomena. As the office pointed out, many reports come from military pilots and concern events in restricted airspace. 
So speculation about aliens aside, the government said its main concerns are safety and national security. 
"[Unidentified aerial phenomena] pose a safety of flight and collision hazard to air assets, potentially requiring aircraft operators to adjust flight patterns in response to their unauthorized presence in the airspace, operating outside of air traffic control standards and instruction," the report said. 
In addition, the Pentagon indicated that UFO reports could help identify "potential adversarial activity" (i.e. foreign nations trespassing on U.S. airspace). The report noted that "the observed increase in the UAP reporting rate is partially due to a better understanding of the possible threats that UAP may represent." 
The classified version of the report noted that many sightings occurred in the airspace near nuclear power plants or storage facilities with nuclear weapons.