A SpaceX Falcon 9 rocket lifts off Sunday from Cape Canaveral Space Force Station carrying a batch of Starlink satellites.

A strange light moved through the East Texas sky last week. For some onlookers, it seemed to vanish into thin air.

It left them with more questions than answers. What was it? Where did it come from, and where did it go?

On social media pages for Tyler-area folks, people posted videos and photos of the celestial glow that they captured around dusk. It didn’t look like a plane, helicopter or drone, and some began to joke or question whether extraterrestrials were to blame.

In reality, East Texans were seeing the upper stage of a rocket that was launched to send new satellites into orbit around Earth. And when people here saw the rocket stage mostly clearly, it already had made a trip around the globe, hence its easterly direction over the Lone Star State, according to Chad File, a mechanical engineering professor at LeTourneau University.

File oversees a student rocketry program, the LeTourneau University Nexus for Amateur Rocketry.

West-east flight

About 5:35 p.m. eastern time (4:35 p.m. central) Sunday, SpaceX — a spacecraft manufacturer founded by entrepreneur Elon Musk — launched one of its Falcon 9 rockets from Cape Canaveral, Florida. The rocket had a mission: Deploy 23 Starlink satellites into low-Earth orbit.

Photos and videos of the luminescence began appearing on East Texas social media pages around dusk Sunday, generating discussion. Like Hank Williams’ hit country song “I Saw the Light,” droves of social media users commented on those posts, testifying that they’d seen it, too.

On Sunday, Longview resident David Salazar took a video of the luminous object by using his phone, and his wife posted it to a Longview community Facebook page.

“I thought, ‘Whoa, what’s that?’” Salazar said. “Immediately after, I saw the ‘boom.’ It shot towards the right and then slingshot back to the left quickly. Then it faded into a poof of smoke.”

Some quickly attributed the light to the SpaceX launch. Others had their doubts: Most videos showed the light moving from west to east — which, at first, didn’t seem possible for a rocket launched from Florida.

File explained that the Falcon 9 rocket loops around the globe — or circumnavigates, scientifically speaking — before its payload is deployed. By dusk, the rocket already had been all the way around the globe, which explains why it was moving from west to east over Texas, as shown in videos on social media, he said.

On its website, SpaceX posts videos that show the flight paths its rockets will take around the Earth.

“The flight path shows — from [Sunday’s] launch, in particular — after it’s reached around the globe, it goes right over Texas,” File said.

Of note is that SpaceX has a facility in far South Texas near Boca Chica Beach and has launched rockets from there.

Payload section was seen

So, which specific part of the rocket were East Texans likely seeing Sunday night?

The second stage, File said. To understand that, here’s a quick rundown of the Falcon 9.

The Falcon 9 — named after the famed Millennium Falcon from “Star Wars” — is a two-stage rocket, according to SpaceX.

The first stage of the rocket gives it more than 1.7 million pounds of thrust for liftoff. That stage falls away from the rest of the rocket and lands at a specific location, where it can be captured and reused. The first stage used Sunday had powered 16 previous missions, according to SpaceX. It landed on a ship about 8.5 minutes after liftoff, news website www.space.com reported.

In between the first stage and the second stage is the interstage, which allows the two stages to separate during flight. It falls away from the second stage.

The second stage, or upper stage, gives the payload its final push into desired orbit, according to SpaceX. The payload — in this case, a collection of satellites — is stored above this section in the fairing, a shell that houses the satellites on their way into space and opens to release them.

Satellites were deployed about 65.5 minutes after liftoff, space.com reported. SpaceX works to recover some parts of the fairing that can be reused.

The same can’t be said, though, for the second stage, which burns up as it reenters Earth’s atmosphere, according to reporting by news website www.cnet.com.

Depending upon the time at which some social media users captured their videos, they may have captured the payload stage’s deorbit burn on its way to Earth rather than one of its trips before sending its satellites into space, File said.

“In one of the videos I saw, there was not like a flash around it, but almost like a halo, cloud-ish, around it,” File said. “And that could just be a remnant of it heating up as it’s reentering thicker atmosphere.”

Re-entry burn-up may be one reason why some folks said they saw the object disappear, File said.

“Another one could be just from the location of the sun relative to that object in the sky,” File said. “Once that object that’s up in the air goes into the shadow of the Earth, then the sun will no longer reflect off of it, and it effectively disappears.”

File gave this illustration: “Anybody who goes out late in the evening after sunset — before like midnight or something — you can often see a satellite up in the sky that looks like a plane, but it’s not blinking. It’ll look like a plane just moving, but you’ll only see it for a certain time, and then it just disappears. And that’s simply — you see the sunlight reflected off of that until a certain point at which you can no longer see the sun reflecting off of it.”

About Starlink

The Sunday rocket mission launched the Starlink satellites into low-Earth orbit, which is “the area in Earth orbit near enough to Earth for convenient transportation, communication, observation, and resupply,” according to NASA. “This is the area where the International Space Station currently orbits and where many proposed future platforms will be located.”

Starlink satellites are another one of Musk’s business ventures. Starlink is a satellite internet provider with a goal of making high-speed internet service, also called broadband, available “almost anywhere on Earth,” according to the company’s website. Some people in East Texas are using the service, as broadband isn’t available in some parts of the region.

Starlink satellites are known for emitting their own unique light that has caused social media stirs. Joined together, they comprise illuminated “satellite constellations,” appearing as if they’re a train of lights passing through the sky.

People can find out when a Starlink constellation will be passing over where they live by visiting the website www.findstarlink.com, which provides approximate time and location information for viewing.

The constellations are “really impressive to see,” File said.