The graves of twin moon probes were discovered by NASA’s Lunar Reconnaissance Orbiter (LRO), which took several photographs of the craters.
The twin Grail probes were crashed into the moon’s surface on December 17, 2012 after they ended their gravity-mapping mission. The probes, named Ebb and Flow, slammed into a mountain near the moon’s north pole going 3,771 mph.
They hit about 20 seconds apart. The Grail probes were running out of fuel and expected to crash soon when the team decided to bring them down in a controlled way, away from areas of historical importance.
The craters were first seen in pictures in January, but the latest images, taken on February 28, show the landing sites in greater detail. Mark Robinson of Arizona State University, the Lunar Reconnaissance Orbiter Camera’s principal investigator, recalled, “It was really fun to find the craters.”
Robinson added that his team was able to use the photos to produce a topographic image of the impact zone. The site was named after Sally Ride, a late NASA astronaut. Ride led the Grail’s educational MoonKAM project before she passed away last July.
Team members also announced on Tuesday that they were able to use the LRO to observe the immediate aftermath of the twin moon probes crashing last December.
They weren’t able to get images of the actual crashes, because they happened while the region was in the dark. However, the orbiter’s ultraviolet imaging spectograph was able to spot emissions from mercury, as well as atomic hydrogen in the ejected plumes.
Ebb and Flow, the stars of the Grail (Gravity Recovery And Interior Laboratory) mission, launched in September 2011. They arrived at the moon about three months later and worked together to race across the moon’s surface, mapping out its gravity field in never-before-seen detail. The project cost $496 million.
The measurements taken by the twin moon probes have let scientists create the best gravity map of any celestial body to date. The Grail probes were the size of washing machines. Grail principal investigator Maria Zuber of MIT stated of the probes, “They dedicated their existence to science.”
[Images via NASA/GSFC/Arizona State University]