A mysterious trail resulting from the launch of SpaceX's Falcon 9 has trended on social media as an alien sighting.

The two-stage rocket took off at 5:27 p.m. on Dec. 22 from the Vandenberg Air Force Base located north of Santa Barbara, California and has been slated to deliver 10 satellites into the Earth's orbit. These satellites are part of the series comprised of 75 satellites that will be used by Iridium Communications to provide mobile voice and data services.

Upon launching, it left behind a glowing streak on the Southern California sky which was visible up to Phoenix, Arizona. This phenomenon was due to exhaust gases ejected by the spacecraft, which were illuminated by the setting sun.

Falcon 9 Launch Causes Both Wonder And Panic

Many residents were amazed by what a report describes as a "dazzling sight." Hany Girgis, a company owner from La Jolla, spotted the whale-shaped trail while out for dinner with friends.

Everyone at the restaurant they were eating at took photos and videos using their devices but none had any idea what the trail was and what caused it. Fortunately, one of Girgis' friends knew about the launch and identified it as the source of the unknown plume.

Even children enjoyed the rare view. Jennifer Garrison, a mother of two from Apple Valley, was spending the holidays with her two sons in Big Bear during the SpaceX launch. Instead of hiding her children, they welcomed the unusual sighting and even took pictures of her sons with the streak in the background.

However, there were others who responded to the sighting with fear. A report says the whale-shaped trail has caused worry over UFOs and a possible nuclear bomb attack by North Korea.

To address concerns raised by panicking residents, the Los Angeles Fire Department has released a statement assuring that the "mysterious light in the sky" was caused by the launch.

SpaceX To Upgrade Satellites Under Iridium NEXT

Iridium NEXT is the satellite communications provider's space project, which goal is to replace or update its existing structures along the Iridium constellation in the low Earth orbit.

Moreover, this undertaking is considered to be the biggest technology-related upgrade in outer space and will enable Iridium Communications to offer improved services, such as larger bandwidth allowances and higher internet speeds.

The Falcon 9 was also used to launch a classified satellite called NROL-76 in May 2017 and a 4,800-pound cargo to the International Space Station.