Since its launch in 2009 by NASA, the Lunar Reconnaissance Orbiter (LRO) has been meticulously scrutinizing every corner of the Moon, revealing its secrets with a clear objective: to map its surface in search of areas suitable for future lunar landings, valuable resources and unique natural phenomena, such as lava tubes. With almost the entire lunar surface under its magnifying glass, except for the perpetual shadows of the polar regions, the LRO has managed to map an impressive 98.2% of our satellite.
Now, in one of these missions, the LRO captured a peculiar image: a tiny object, similar to a splinter or a surfboard, flying through lunar space at high speed. As expected, this vision has generated great curiosity and speculation in the media due to its “mysterious” appearance. However, far from what might seem like an unsolved enigma, the explanation is quite earthly and has to do with a remarkable spatial coincidence.
It turns out that the mysterious traveler was none other than the Korea Pathfinder Lunar Orbiter (KPLO), better known as Danuri, belonging to the Korea Aerospace Research Institute. This device, which follows a trajectory almost parallel to that of the LRO, crossed the latter’s field of vision, resulting in an extraordinary photographic capture that required perfect synchronization, given the high speeds at which both were moving, more of 3.2 kilometers per second.
“Due to the fast relative speeds between the two spacecraft (about 11,500 kilometers per hour), the LRO operations team at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, required exquisite timing to point LROC to the location. right at the right time to catch a glimpse of Danuri, the Republic of Korea’s first spacecraft on the Moon,” NASA explained.
South Korea launched its ambitious Danuri project into orbit in August 2022, marking a milestone as its first lunar orbiter. Danuri’s mission is not minor: it is in charge of developing advanced technologies, such as the space Internet, and preparing a detailed topographic map of the lunar surface.
To capture the Danuri images, the LRO had to make millisecond timing adjustments and use very fast shutter speeds from a maximum altitude of 8 kilometers. Despite these efforts, the encounter speed between the two orbiters, which reached 11,500 km/h, made a certain degree of blurring in the images inevitable, making Danuri appear more like a small fragment than a spacecraft traditional with solar panels and an antenna.
“Although the exposure time of the LRO camera was very short, only 0.338 milliseconds, Danuri still appears blurry up to 10 times its size in the opposite direction of travel due to the high relative travel speeds between the two spacecraft,” he clarified. The NASA.
In addition to capturing this rare image, the LRO has contributed significantly to lunar knowledge, from identifying debris from failed moon landings to interacting with India’s Vikram lander via a laser.
In an interesting turn of events, last year Danuri’s NASA-designed ShadowCam captured images of the LRO in a role swap, showing the rear of the US probe reflecting the sun’s rays as Danuri flew overhead. approximately 18 kilometers high.