Shortly before 10 p.m., residents reported seeing what appeared to be a long, thin white line streaking across the sky.
"It's like this long strand of light. It's fading away," said one FOX 32 viewer in a video. "Was it some missile? It's too slow for a shooting star."
Mike McFadden, of Warrenville, also reported seeing something similar in western suburban DuPage County.
"That is the strangest thing I have ever seen in my life. Never seen anything like it. That is the weirdest thing ever," McFadden said in the video.
According to Jennifer Howell, spokesperson for Chicago's Adler Planetarium, the mysterious light was nothing to be alarmed about at all.
"Those are Starlink (SpaceX) satellites," Howell told FOX 32. "There are 53 of them & they were launched yesterday [Thursday]. Those folks caught them in the sky as they just started to string out after release. Very cool that they got to see that!"
According to a statement on SpaceX's website, tech entrepreneur Elon Musk's space exploration company launched a Falcon 9 rocket at Cape Canaveral Space Force Station at 12:51 p.m. with 53 Starlink satellites aboard.
The lights also unsettled a number of residents in Southeast Michigan, according to a report from FOX 2 Detroit.
"The ‘lights’ traveled as one, never broke formation, moving from northwest to south," wrote one FOX 2 viewer in an email.
What is Starlink?
Musk, ever the aspiring inventor, has deployed a plan to bring high speed broadband internet to the world. Using his company SpaceX, Musk has plans to launch around 12,000 Starlink satellites over the next few years.
The sudden surge of new satellite launches - about 600 a year - could be contributed to an increase in UFO sightings recently.
While an audacious plan, Musk has already gotten permission to fly 12,000 satellites, and perhaps as much as 30,000 in the future.
The satellites orbit at about 340 miles above the surface.
FOX 2 Detroit contributed to this report.