US Marks 40 Years Since Man First Walked on the Moon

What Apollo Actually Achieved: The Scientific Legacy

Six Apollo missions landed on the moon between July 1969 and December 1972. Apollo 11, 12, 14, 15, 16, and 17 landed 12 astronauts on the surface, returning 842 pounds (382 kilograms) of lunar rocks, soil, and core samples. These samples remain the foundation of lunar science and are still actively studied. A 2024 study published in Nature Geoscience used Apollo 17 samples to determine that the moon is approximately 40 million years older than previously estimated, revising the lunar formation date to about 4.46 billion years ago.

Apollo's scientific instrumentation also included seismometers, which detected moonquakes and helped map the lunar interior structure, retroreflectors (still used today to bounce laser beams from Earth to precisely measure the Earth-Moon distance, currently about 384,400 kilometers and increasing by 3.8 centimeters per year), and magnetometers that helped establish the moon's lack of a global magnetic field.

The Apollo program also advanced materials science, life support engineering, and telecommunications in ways that filtered into civilian technology for decades. The integrated circuit, which made miniaturized electronics possible, was partly driven by Apollo's demand for compact, reliable computing. The program cost approximately $25.4 billion in 1973 dollars, which translates to roughly $257 billion in 2026 dollars, making it one of the largest peacetime government investments in science and engineering in history.

We are still learning from those samples. Every time analytical techniques improve, we go back to Apollo 15, Apollo 17, and we find something we could not see before. The collection is scientifically inexhaustible.Dr. Jessica Barnes, Lunar Scientist at the University of Arizona's Lunar and Planetary Laboratory, speaking to Space.com, 2024

What Apollo did not do, and this matters for understanding what Artemis is trying to accomplish, is establish a permanent presence. Each landing was a sortie: land, collect, leave. Apollo 17's Eugene Cernan and Harrison Schmitt, the only professional geologist to walk on the moon, spent 75 hours on the surface in December 1972 and then departed. No human has been above low Earth orbit since.

Apollo vs. Artemis: A Comparison Across Six Decades

Artemis II: Four Astronauts, One Critical Mission

The Artemis II mission, currently targeting early April 2026 for launch from Kennedy Space Center's Launch Complex 39-B, will not land on the moon. It is designed to do something more foundational: prove that the Orion capsule's life support and navigation systems work with humans aboard, following the uncrewed Artemis I test flight in late 2022.

The crew consists of Reid Wiseman (NASA, commander), Victor Glover (NASA, pilot, the first Black astronaut to fly on a lunar mission), Christina Koch (NASA, mission specialist, the first woman assigned to a lunar mission), and Jeremy Hansen (CSA, mission specialist, the first Canadian assigned to a lunar mission).

The mission profile calls for a day orbiting Earth to verify all systems, then ignition for lunar transit taking three to four days. Artemis II will not enter lunar orbit but will swing around the far side of the moon and use lunar gravity to slingshot back toward Earth, a free-return trajectory that minimizes propellant and mirrors the path Apollo 13 used to get its crew home after their 1970 emergency. At its farthest point, the crew will travel approximately 5,000 miles beyond the moon, exceeding the distance record set by Apollo 13 and extending humanity's farthest distance from Earth.

The Apollo program still just absolutely blows me away. What they accomplished with the technology they had is staggering. But there is no way we could be that same mission or ever hope to be. We are a different program with different goals.Christina Koch, NASA Astronaut, Artemis II Mission Specialist, speaking at pre-launch media briefing, March 2026

The Artemis program's broader architecture, as revised by NASA administrator Jared Isaacman in early 2026, now targets Artemis III (formerly a landing mission) as an Earth-orbital practice of docking procedures with the lunar landers under development by SpaceX and Blue Origin. The actual moon landing has been moved to Artemis IV, currently targeting 2028. Isaacman has explicitly framed the competition with China's stated goal of landing astronauts near the lunar south pole by 2030 as a motivating factor in the revised timeline.

"The Apollo program still just absolutely blows me away," said Jeremy Hansen in pre-launch media availability. "That generation of engineers and astronauts did something that required absolute commitment from the entire country."

Why the South Pole Matters: Water, Ice, and What Comes Next

Apollo landed near the lunar equator for a simple reason: sunlight. Solar panels work best in direct sunlight, and equatorial regions on the moon offer predictable illumination. The lunar south pole is a fundamentally different environment, and its scientific and strategic value derives from one factor: permanently shadowed craters.

The moon's axial tilt is only 1.5 degrees, compared to Earth's 23.5 degrees. This means that some craters at the poles have not seen direct sunlight in billions of years. Inside those craters, temperatures drop to approximately minus 250 degrees Celsius (-418 Fahrenheit). NASA's LCROSS mission in 2009 confirmed the presence of water ice in these permanently shadowed regions, and subsequent analyses of data from NASA's LRO have suggested the ice deposits are substantial, potentially billions of tons.

Water ice at the lunar south pole is significant for two reasons. First, it can be split into hydrogen and oxygen, which are the components of rocket fuel. A lunar south pole base that can manufacture its own fuel would dramatically reduce the cost of deep-space missions, including eventual crewed missions to Mars. Second, the ice represents a preserved record of the early solar system, containing water delivered by comets and asteroids over billions of years.

For readers interested in other areas of active space science, our coverage of Mars dust storms blasting water into space examines how Mars is losing water differently than once thought, and our feature on the oldest recorded supernova provides context on the deep-time astronomical events that shaped the solar system Apollo and Artemis are exploring.

What We Still Don't Know

Fifty-seven years after Apollo 11, the moon has yielded remarkable scientific data but also retains significant mysteries. The origin of lunar water remains debated: was it delivered by comets, asteroids, or produced through interactions between solar wind hydrogen and oxygen in lunar soil? The exact thermal history of the lunar interior, and whether the moon retains a partially molten core, is still being refined. The nature and extent of the lunar swirl formations, magnetized patches on the surface associated with unusual regolith properties, is not fully explained.

The lunar south pole presents its own scientific unknowns. No mission has directly sampled the permanently shadowed crater floor environments where ice has been detected. The mineralogy, volatiles content, and age of those ice deposits are inferred rather than measured. Artemis surface missions beginning with Artemis IV, planned for 2028, will be the first to address these questions with human geologists on-site, a capability that robotic missions cannot replicate for complex geological sampling tasks.

NASA's $20 billion, seven-year investment in the Lunar Gateway station (a small space station in lunar orbit that will serve as a staging point for surface missions) and surface infrastructure reflects a fundamentally different ambition than Apollo. Apollo was a race with a finish line. Artemis, if the political will holds across multiple presidential administrations, is meant to be the beginning of a permanent presence, the first chapter of what NASA's new administrator Isaacman has described as eventually an "arc" from lunar orbit to lunar surface to Mars.

Whether that arc sustains over the decades it will require is genuinely uncertain. Apollo 11 happened because one president made a specific promise in 1961 and the nation held to it for a decade. The political economy of sustained space investment across multiple administrations is a harder problem than the engineering.