A camera atop Hawaii’s tallest mountain has captured what appears to be a spiral swirling across the night sky.

Researchers believe that the strange phenomenon is related to a military GPS satellite launched from a SpaceX rocket in Florida.

The images were captured on January 18 by a camera at the summit of Mauna Kea, outside Japan’s Subaru Telescope National Astronomical Observatory.

A time-lapse video shows a white ball spreading out and forming a vortex as it moves across the sky. Then it fades and disappears.

Ichi Tanaka, a researcher at the observatory, said he was doing other work that night and didn’t see him right away. Then a stargazer watching the camera’s live feed on YouTube sent a screenshot of the spiral using an online messaging platform.

“When I opened Slack, this is what I saw and it was an amazing event for me,” said Tanaka. He saw a similar vortex last April, also after the launch of SpaceX, but that was larger and fainter.

SpaceX launched a military satellite on the morning of January 18th from Cape Canaveral Space Force Station in Florida. The location of the helix matched where the second stage of the SpaceX rocket was expected to be after launch.

SpaceX did not respond to an email seeking comment.

Tanaka said the observatory has installed the camera to observe the surroundings outside the Subaru Telescope and shared images of Mauna Kea’s clear skies. He said someone watching the sky in less clear conditions, say from Tokyo, might not have seen the snail.

The live broadcast is run in association with the Japanese newspaper Asahi Shimbun, and often draws hundreds of viewers. Some people tune in to watch meteors.

Mauna Kea summit has some of The best viewing conditions on Earth for astronomy, making it a favorite place for the most advanced observatories in the world. top too It is considered sacred by many Native Hawaiianswho look upon it as a place where the gods dwell.