PHOENIX — Tuesday may have seemed like just another day for some, but for others, it marked another night with a UFO spotted in the skies over Phoenix.

Twitter began lighting up — no pun intended — about 6 p.m. Users described strange lights in the sky for about 45 minutes. And then they … disappeared.

At least one person caught the lights on video and posted it to Twitter (WARNING: EXPLICIT LANGUAGE).

In the video, it appears the lights are twinkling in a pattern that moves from right to left.

While we’re not sure what Tuesday’s sighting may have been, it is far from the first UFO sighting reported in the Valley.

Earlier this year, an employee at Phoenix Sky Harbor International Airport said a massive, chevron-shaped UFO flew over him about 9 p.m. while he was taking out the trash.

“The lights were what I noticed at first,” the worker said in a report. “They were white and formed a chevron shape that allowed me to notice the shape of the object. It was very large as it passed beside me. I was near the tower, so I knew it was high, but not too high as for me not to get an idea how large this object was.”

Other sightings have been reported, but none are as famous as the so-called Phoenix Lights. The incident captured the world’s attention after more than 10,000 people claimed to see another chevron-shaped craft fly over the city on March 13, 1997.

The mystery behind the Phoenix Lights — which were also seen as far away as Las Vegas and Sedona — has never been solved.