We visualize our Moon as a lifeless constant. The polite ebb and flow of lunar cycles, familiar photographs of craters and desolate landscapes. Nary a thought to what might lurk beneath that comfortably stark surface. Does it have a hot core like Earth, or did it once froth with geologic intensity?
In 1971, Apollo 15 astronauts captured images of a lunar anomaly dubbed Ina- by all appearances, the aftermath of volcanic eruption. Science knows the adolescent moon was turbulent – much of the lunar surface is covered in basaltic flows, features of the “man in the moon” were created by seething lava. Science believed lunar vulcanism ceased a billion years ago – Ina raised eyebrows, presenting itself as mysteriously recent.
NASA’s Lunar Reconnaissance Orbiter (LRO) has identified 70 sites similar to Ina, anomalies called irregular mare patches (IMP’s). Lightly cratered, these features have rewritten the geologic timeline of conventional thinking. Consider the possibility of volcanic eruptions 50-100 million years ago. Lunar eruptions during the time of dinosaurs might not seem like a remarkable ponder – I assure you, the leap from a billion to 50 million years is an astounding geologic mind blower.
The next time you catch sight of the moon, smile and ponder the possibility of a churning molten core under all that moonlit familiarity.