A curious piece of footage filmed by a pilot flying over Utah's Zion National Park shows an odd unidentified flying object hovering in the sky below the aircraft. The strange encounter reportedly occurred back in September, but the video captured by the unnamed witness only surfaced online late last week when it was posted to the Mutual UFO Network's YouTube channel.

According to the organization, "the video was recorded while flying at approximately 40,000 feet." MUFON went on to indicate that "internally we are categorizing this case as a 'case of interest,' which is a designation applied to cases which have significant circumstances associated with them." The group also says that the "case investigation is in its initial stages" and, as of now, no explanation for the oddity has been offered.

As is often the case with hard to decipher footage of anomalous objects in the sky, there has been no shortage of suggestions for what the oddity might have been. Theories offered by observers online include some kind of weather balloon, a secret government test craft, a smudge on the window of the plane, and, of course, aliens. With that in mind, check out the video and share your best guess for the nature of the UFO at the Coast to Coast AM Facebook page.