Sea of Night

Aepinus crater rim seen in winter
Rim of Aepinus crater rising above a sea of dark during a winter night. Illuminated area 1.5 kilometers by 6.0 kilometers, NAC M1338480133LR [NASA/GSFC/Arizona State University].

On 10 March 2020, LRO rolled (tilted the spacecraft to the side) 50° allowing the LROC to capture this amazing view of high terrain illuminated before sunrise. Such small areas that receive abnormally long periods of illumination could be valuable to future lunar explorers. The lunar night lasts over 300 hours,  and the temperature drops below –170°C (–274°F), so any extra time in the sunlight can provide welcome warmth and solar power.

Reduced resolution (40x) of full panoramic voew of Aepinus crater
Reduced resolution (40x) of the full oblique view of the Aepinus crater (87.96°N, 250.3°E) rim rising above the dark, 80 kilometers beyond the terminator (day/night boundary).  Image width 110 km, north is towards the lower right, NAC M1338480133LR [NASA/GSFC/Arizona State University].

Also near the poles there exist areas of permanent shadow, regions which are so cold (–210°C (–346°F) and lower!) that water ice can exist on the surface even under the vacuum of space. The combination of terrain that sees extra illumination by peeking above the horizon, adjacent to low-lying permanently shadowed regions (PSRs) that contain ice, makes these very compelling regions to set up camp. These two important resources – sunlight and water – can help to sustain longer stays on the Moon, or propel explorers from the Moon to more distant locations.

WAC context view of Aepinus illuminated rim
LROC Wide Angle Camera context image taken at nearly the same time as the NAC image shown above; the barely visible rim of Aepinus crater (indicated with arrows in the upper right) is 96 kilometers from the center of Gore crater. M1338480130C (415 nanometer band) [NASA/GSFC/Arizona State University].

Explore the full resolution NAC of this spectacular persistenly illuminated peak.

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Published by Mark Robinson on 19 May 2020