Some eagle-eyed humans looking skyward this weekend saw something against the brilliant-blue backdrop that had them questioning what the heck was flying above.
If this were last century, they probably would've thought first of alien spaceships.
But UFOs are so 20th-century.
These days, flying objects can be so much more odd, even when they have terrestrial origins.
In the case of what flew over the Philadelphia region this weekend, the answer likely involves a company so often at the center of our collective cultural discussion: Google.
The objects seen by at least a handful of observers are, essentially, flying WiFi routers created by a company called Loon, which is a division of Google's parent corporation, Alphabet.
An official with Loon confirmed to NBC10 Philadelphia that "a number of balloons" were flying over southeastern Pennsylvania and the surrounding area during the last couple days.
Skyler Connery sent in this video to NBC10 of a balloon flying over Media, Delaware County, on Saturday. The Loon balloon in his video is magnified 150 times using a telescope and camera, Connery noted, adding that it "looked like a daylight star to the naked eye."
Loon spokesman Scott Coriell said in an email that the balloons can fly 60,000 feet above the Earth, well above commercial airplanes and wildlife.
"On any given day, Loon has dozens of balloons flying around the world as part of ongoing testing of our balloon-powered internet system. We routinely conduct this testing in the U.S.," Coriell said. "The balloons are designed to last for hundreds of days in the stratosphere. When a balloon is ready to land, we navigate it to a sparsely populated area. The helium keeping the balloon aloft is released, and a parachute deploys to guide the balloon slowly to the ground. We then dispatch recovery teams to collect the balloon for analysis and recycling."
Coriell said the Loon balloons have already showed their value in providing internet to those in catastrophe-struck regions of the world.
"In the past few years, the Loon system has been used to connect hundreds of thousands of people, most recently in response to the 8.0 magnitude earthquake that struck Peru in May," Coriell said. "To date, Loon's balloons have flown over 40 million kilometers — enough to circle the earth 1,000 times."
Here's what the balloons looked like to the naked eye Saturday, as captured in video submitted by Wayne Masters in Whitemarsh Township, Montgomery County.
Loon's mission, according to Coriell, "making it possible to extend internet access to the billions who currently lack it. Using a network of balloons traveling on the edge of space, Loon works with mobile network providers to expand coverage to unserved and underserved populations, upgrade existing networks and provide expedient coverage after natural disasters."