3 Questions: Ben Weiss on the lunar dynamo
When the Apollo astronauts returned to Earth, they brought with them some souvenirs: rocks, pebbles, and dust from the moon’s surface. These lunar samples have since been analyzed for clues to the moon’s past. One outstanding question has been whether the moon was once a complex, layered, and differentiated body, like the Earth is today, or an unheated relic of the early solar system, like most asteroids. Ben Weiss, a professor of planetary sciences in MIT’s Department of Earth, Atmospheric and Planetary Sciences, and members of his laboratory have found remnants of magnetization in some lunar rocks, suggesting that the moon once emitted a substantial magnetic field, much like the Earth does today. The discovery has opened a new set of questions: How long did this magnetic field last? How strong was its pull? And what sparked and sustained it? Weiss and former MIT student Sonia Tikoo have written a...