What were those lights in the sky over southeastern Pennsylvania?

A string of lights flying over Delaware County drew the attention of a Wallingford resident about 9:30 p.m. Thursday when he saw it above his home.

The man described the lights as looking like a group of drones flying in a straight-line formation high in the sky.

"There was no noise. The lights appeared to be headed in the general direction of Philadelphia," he said. "We had eyes on it for 2-3 minutes before it flew out of view."

The resident, who did not want to give his name, took video.

He was concerned that whatever it was may interact with the airliners going in and out of Philadelphia International Airport.

It turns out the lights were from SpaceX Starlink trains, satellites launched by Elon Musk. They are best seen when first launched.

Starlink is a network of more than 2,000 satellites orbiting more than 340 miles above the Earth to provide high-speed broadband internet around the world.

The Franklin Institute's chief astronomer Derrick Pitts confirmed the lights were SpaceX Starlink Internet satellites. Similar sightings were reported around the U.S.

"It's called a satellite ‘train’ and is a string of satellites within hours after launch, just after deployment from the rocket, zooming along on their orbital path," Pitts said. "They will eventually spread out so they are equidistant, forming a ring around the Earth. Once in final position on orbit, they will be less visible to casual observers."

Pitts noted that astronomers have been warning that the satellites will become an impediment to astronomical research because they will eventually show up in every image of the night sky taken by astronomers doing research.

"The planned total number of satellites Starlink proposes to use is about 12,000," Pitts exclaimed.

The satellite network is intended to provide high-quality, low-cost internet access from anywhere in the world.

Pitts suggested readers watch this YouTube video: https://www.youtube.com/watch?v=QV5rCP7uiaU.

Pitts said there will be a string of at least 50 passing over Philadelphia tonight at 9:41 p.m., 56 degrees above the north-northwest horizon.

"Somewhat dim, but certainly visible in binocs, just not downtown: Too much light pollution," he said.

The website https://findstarlink.com reports the visibility of the satellites. It confirms they were visible over Delaware County and southeastern Pennsylvania for about five minutes on Thursday beginning at 9:24 p.m.

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