A team of scientists made the shocking discovery that some cosmic filaments, which are the largest known structures in the entire universe, are rotating around their central axis like gigantic drills, according to research published Monday in the journal Nature Astronomy.

But that’s as far as they got, Space.com reports: The team has no idea why the filaments started to spin or what force could have been powerful enough to set them in motion.

“We’re not really sure what can cause a torque on this scale,” study coauthor Noam Libeskind told Space.com.