A pair of lunar orbiters recently crossed each other’s paths around the Moon, with one flying overhead and capturing an image of the orbiting spacecraft below. The Korea Pathfinder Lunar Orbiter, also known as Danuri, snapped the streaked, fuzzy photo of NASA’s Lunar Reconnaissance Orbiter (LRO) as both spacecraft circled the Moon.
This wasn’t entirely a coincidence, though, as the two mission teams coordinated the orbital rendezvous. On April 7, LRO passed about 11 miles (18 kilometers) below Danuri, enabling the Korean orbiter to capture the image at a relative velocity of 11,447 km per hour (3,180 meters per second) between the two spacecraft, according to the team behind NASA’s ShadowCam.
NASA’s LRO team members steered their spacecraft around 20 degrees away from the Sun so that its radiator and the back of the orbiter could be brightly illuminated for the photo-op. The resulting image shows a fuzzy view of the Reconnaissance Orbiter, which has been orbiting the Moon since 2009.
The image was captured by NASA’s ShadowCam on board the Korean Pathfinder, a light-sensitive camera capable of operating in extremely low light. ShadowCam has a sibling camera on board LRO, which is famous for snapping its own images of other lunar spacecraft such as NASA’s Lunar Atmosphere and Dust Environment Explorer and the Gravity Recovery and Interior Laboratory.
The team behind ShadowCam created a simulated image of LRO using an accurate model of the spacecraft, including its orientation and components relative to both the Sun and Danuri. The image above shows a clearer, computer-generated view of the pixelated black-and-white image, though it appears four times in the frame due to the relative speed of the two spacecraft and limitations having to do with exposure times, among many other factors.
Danuri’s NASA-funded hypersensitive optical imager recently captured some stunning views of the Moon’s permanently shadowed regions. South Korea’s first deep space mission launched in August 2022 to explore possible hidden reservoirs of ice water on the Moon.
The lunar orbit encounter between the two spacecraft will forever be marked by that fuzzy image of LRO’s best angle.