Magnetism on the moon
In the nearly five decades since the first lunar surveys were conducted as part of NASA’s Apollo space program, scientists have advanced a number of increasingly complex theories to explain the vast swaths of highly magnetic material that were found in some parts of the moon’s crust. But now a team of researchers from Harvard, Massachusetts Institute of Technology, and the Institut de Physique du Globe de Paris have proposed a surprisingly simple explanation for the unusual findings, suggesting that the magnetic anomalies are remnants of a massive asteroid collision. As described in a paper published March 9 in Science, the researchers believe that an asteroid slammed into the moon approximately 4 billion years ago, leaving behind an enormous crater and iron-rich, highly magnetic rock. While there is evidence that the moon once generated its own magnetic field, there is little to suggest it was strong enough to account for the anomalies...