A rare lunar transit allowed amateur astrophotographer Efrain Morales to capture China’s Tiangong space station as it passed across the face of the Moon. Recorded from Puerto Rico on May 29, the event lasted less than a second and revealed the station’s silhouette against one of the Moon’s most recognizable regions. As reported by Space.com, the transit took place at 11:33 p.m. EDT on May 29, one night before May’s Blue Moon.
Lunar transits by spacecraft are among the most demanding astronomical events to photograph. Because the alignment between the observer, the Moon, and an orbiting station is so precise, the opportunity is visible only from a narrow path on Earth and disappears almost instantly. Capturing such a moment requires careful preparation, accurate predictions, and equipment capable of recording high-speed imagery.
In this case, the transit also highlighted the distinctive structure of Tiangong. The station’s silhouette briefly crossed familiar lunar landmarks, producing a striking contrast between a modern orbital laboratory and geological formations that have existed for billions of years.
A Perfect Observation in Under One Second
Efrain Morales recorded the transit using a 12-inch telescope paired with an astronomy camera. The footage clearly outlines Tiangong’s expansive solar panels and its habitable modules as the station crossed the illuminated lunar surface.
Morales explained that photographing this type of event requires precise preparation because the transit lasts for less than a second. In an email to Space.com, he described the challenge of capturing such a brief alignment.
“It is a challenge in less then a second to capture this event. Using a program the ISS Transit Finder helps in giving information to capture the space station. Adjusting the FOV and at times calculating last minute deviations in time and positions in which makes it more challenging.”
The software helped predict the transit, while final adjustments were still necessary to account for slight changes in timing and position before the station crossed the Moon.
Tiangong Over Lunar Landmarks
The recorded transit gives the impression that Tiangong is descending directly toward Tycho Crater, one of the Moon’s most prominent impact structures. The crater spans approximately 53 miles (85 kilometers) and is surrounded by bright ejecta rays that become especially visible during the nights around the full Moon.
As noted by the same source, other familiar features are also visible in the footage. Mare Nubium, known as the Sea of Clouds, appears to the left of the transit, while Mare Nectaris, or the Sea of Nectar, is visible toward the upper right.
These dark plains were formed billions of years ago when ancient lava flows cooled into broad basaltic surfaces. Their appearance in the video provides recognizable reference points while emphasizing the rapid movement of the orbiting station across the lunar disk.
Shenzhou 23 Continues Its Orbital Mission
Tiangong, whose name translates as“Heavenly Palace” from Mandarin, consists of the Tianhe core module along with the Wentian and Mengtian laboratory modules. Together, the three modules form China’s permanently crewed space station, which orbits Earth at an altitude ranging between 217 and 280 miles (340 to 450 kilometers), completing multiple trips around the planet every day.
Space.com reports that the orbital outpost is currently occupied by the three astronauts of the Shenzhou 23mission. The crew includes commanderZhu Yangzhu, pilot Zhang Zhiyuan, and payload specialist Lai Ka-ying. The three crew members launched aboard a 203-foot (62-meter) Long March 2F rocket on May 24 and are now living and working aboard the station.
