When NASA’s Artemis II mission sends four astronauts on a 10-day journey around the moon, they won’t just be reenacting Apollo. They’ll be observing terrain that no human has directly seen with the naked eye — particularly on the lunar far side.
Unlike Apollo crews, whose orbital paths focused on equatorial regions of the near side for communication and safety reasons, Artemis II’s trajectory could offer a broader, higher-altitude perspective. From roughly 4,000–6,000 miles above the surface, the Orion capsule will reveal the full lunar disk, including polar regions and permanently shadowed areas that rarely receive sunlight.
Why the far side matters
The moon is not symmetrical. The near side — the one visible from Earth — has:
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Thinner crust
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Large volcanic plains (maria)
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Higher concentrations of heat-producing elements
The far side, by contrast, has:
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Thicker crust
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Fewer volcanic basins
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Higher elevation overall
This global asymmetry remains one of the biggest unanswered questions in lunar science.
One candidate for explaining this imbalance is the South Pole–Aitken basin, a massive impact structure roughly 2,500 km wide and over 8 km deep. It may be the oldest large crater on the moon. Precisely dating it could reshape our understanding of early solar system history.
Apollo answered big questions — and created new ones
Samples returned during the Apollo era revealed that the moon likely formed after a Mars-sized body collided with early Earth, ejecting molten material that eventually coalesced into the moon. Evidence supporting this includes:
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Isotopic similarities between lunar rocks and Earth’s mantle
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Widespread anorthosite, suggesting a global magma ocean
But Apollo missions sampled only a small portion of the lunar near side — around 5% of the surface has ever been directly sampled. That leaves huge geological blind spots.
If we want to understand what the moon was like before major impact events such as Mare Imbrium (~3.9 billion years ago), we need samples from regions that weren’t resurfaced by those events — especially the south pole and far side.
What Artemis II specifically adds
Artemis II is not a landing mission. It’s observational. But trained astronaut observers can contribute something robotic orbiters cannot: contextual, adaptive interpretation in real time.
The crew may:
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Photograph far-side craters and lava flows
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Observe transitional regions like the Orientale basin
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Capture possible impact flashes from micrometeorites
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Study subtle dust phenomena near the lunar limb
Because the mission flies at higher altitude than Apollo command modules or the Lunar Reconnaissance Orbiter, it offers a systems-level perspective of the moon as a whole object.
The south pole: ice and seismic activity
Future Artemis landings (Artemis III and beyond) aim for the lunar south pole. That region contains permanently shadowed craters where water ice may be trapped.
Open questions include:
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How much ice exists?
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Where did it originate? (Comet delivery? Solar wind? Interior outgassing?)
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How does it relate to Earth’s water history?
Seismometers placed in new locations could also help map the moon’s internal structure and clarify why its near and far sides evolved so differently.
Bigger picture: Earth, moon, Mars
Studying the moon is not just about lunar geology. It informs:
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Early Earth history (much of which has been erased by tectonics and erosion)
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Impact rates in the early solar system
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Planetary stabilization and climate evolution
The moon’s presence likely stabilized Earth’s axial tilt — a factor believed to be important for long-term climate stability and possibly life itself.
In that sense, the moon acts as both archive and control sample for understanding terrestrial planet formation.
Open question
Apollo transformed lunar science but sampled only a narrow equatorial band. Artemis could expand that dataset significantly.
If the South Pole–Aitken basin turns out to predate known heavy bombardment timelines — or if polar ice isotopes challenge current formation models — it could force revisions to early solar system history.
Given how much Apollo changed planetary science, what’s the most likely “textbook rewrite” Artemis could trigger next?
