Moon Science: Fences on the Moon? | NASA's Lunar Reconnaissance Orbiter

Moon Science: Fences on the Moon? | NASA's Lunar Reconnaissance Orbiter

Mysterious farside impact melt deposits, image width 12 kilometers at center, looking west-to-east, north is to the left, M1451669615LR.

Full-resolution view showing impact melt that ponded in the bottom of a 10-kilometer diameter crater. The dark lines (fences) formed as impact melt flow fronts solidified, not quite making it down to crater bottom. The flow fronts are so dark because they are very blocky and the Lunar Reconnaissance Orbiter Camera (LROC) was looking back towards the Sun enhancing topographic shadows. The flat ponded impact melt rock deposit is 600 meters by 800 meters wide, north is to the left NAC M1451669615

This complete Narrow Angle Camera (NAC) oblique perspective shows a portion of the enigmatic highland pond area. Image width is approximately 72 kilometers in the center; north is to the left, NAC M1451669615LR

Fences on the Moon?

Early in the Lunar Reconnaissance Orbiter (LRO) mission, Lunar Reconnaissance Orbiter Camera (LROC) images of the central farside revealed impact melt deposits with no prominent source crater. Very mysterious. Soon, scientists noticed that these enigmatic deposits were found at the Tycho crater antipode (opposite side of the Moon). Perhaps the Tycho forming event was so energetic that it ejected melt to the opposite side of the Moon, a distance of 5400 kilometers requiring a time-of-flight of 164 minutes. M1451669615, looking west-to-east, acquired 2023-10-11, incidence angle 60°, slew angle 47°, phase angle 110°, spacecraft altitude 112 kilometers, image width 12 kilometers.

Details in the first image highlight what appear to be "fences". Then, the full-resolution view (second image) shows impact melt that ponded in the bottom of a 10-kilometer diameter crater. The dark lines (fences) formed as impact melt flow fronts solidified, not quite making it down to crater bottom. The flow fronts are so dark because they are very blocky and LROC was looking back towards the Sun enhancing topographic shadows. The flat ponded impact melt rock deposit is 600 meters by 800 meters wide, north is to the left NAC M1451669615.

The third image is a complete Narrow Angle Camera (NAC) oblique view presenting a portion of the enigmatic highland pond area. Image width is approximately 72 kilometers in the center; north is to the left, NAC M1451669615LR. 

This year, NASA's Lunar Reconnaissance Orbiter (LRO) celebrates its 16th anniversary orbiting the Moon (2009-2026). This mission has given scientists the largest volume of data ever collected by a planetary science mission at NASA. Considering that success and the continuing functionality of the spacecraft and its instruments, NASA awarded the mission an extended mission phase to continue operations. LRO continues to be one of NASA's most valuable tools for advancing lunar science.

Image Credit: NASA/GSFC/Arizona State University

Text Credit: Mark Robinson

Release Date: April 25, 2025

#NASA #Space #Astronomy #Science #Earth #Moon #Geology #Geoscience #Craters #ImpactCraters #MeltDeposits #ArtemisProgram #LRO #LunarOrbiter #LROC #NAC #SpaceRobotics #SpaceTechnology #GSFC #UnitedStates #SolarSystem #SpaceExploration #STEM #Education