Footage captured by YouTuber Anders Otteson shows a mysterious, UFO-like object being tested at Lockheed Martin’s secretive Helendale Skunk Works facility in the California desert.

The site, known for developing classified aircraft like the U-2, SR-71, and F-117, has fueled speculation about advanced or even alien technology projects.

The object, possibly part of early testing for a new aircraft or drone, has led to theories it could be the hypersonic SR-72 “Darkstar,” capable of Mach 6 speeds and global reconnaissance, the U.S. Sun has reported.

Despite public intrigue, neither Lockheed Martin nor the US Air Force has officially confirmed the craft’s existence or purpose.