Solar wind has carried particles from Earth’s atmosphere to the moon for billions of years, embedding them deep within lunar soil. This major discovery, published in Nature Communications Earth & Environment, addresses a half-century-old mystery about why Apollo samples contained traces of water, carbon dioxide, and nitrogen.
While scientists previously believed Earth’s magnetic field prevented these particles from escaping, a new study from the University of Rochester suggests the opposite. The field actually helps the process by creating a “magnetotail”—a cosmic channel that directs atmospheric gases to the moon, especially when it passes through Earth’s shadow during a full moon.
“This means that the Earth has been supplying volatile gases like oxygen and nitrogen to the lunar soil all this time,” said coauthor Eric Blackman.
The implications for space exploration are significant. Blackman noted that future lunar colonies could harvest these trapped elements to produce fuel and support systems, reducing the need to transport heavy supplies from Earth. “There are also studies of ammonia-based fuel, which would take advantage of the nitrogen carried onto the moon,” he added.
Lead author Shubhonkar Paramanick and his team compared their computer simulations with lunar samples gathered by Apollo 14 and 17 astronauts. Their findings suggest that Earth’s current strong magnetic field is more efficient at transferring atmospheric fragments than a less magnetized, ancient Earth would have been.
External experts call the findings “highly exciting.” Kentaro Terada of Osaka University confirmed that the study theoretically corroborates his earlier observations of oxygen transport. Furthermore, the research suggests the moon acts as a “time capsule,” holding a frozen chemical record of Earth’s ancient atmosphere and the evolution of life.
New soil samples collected during China’s recent Chang’e-6 mission are expected to be used by scientists for further testing of these findings.