The team's findings suggest the moon possesses a solid, iron-rich inner core with a radius of nearly 150 miles and a fluid, primarily liquid-iron outer core with a radius of roughly 205 miles. Where it differs from Earth is a partially molten boundary layer around the core estimated to have a radius of nearly 300 miles. The research indicates the core contains a small percentage of light elements such as sulfur, echoing new seismology research on Earth that suggests the presence of light elements -- such as sulfur and oxygen -- in a layer around our own core.
The researchers used extensive data gathered during the Apollo-era moon missions. The Apollo Passive Seismic Experiment consisted of four seismometers deployed between 1969 and 1972, which recorded continuous lunar seismic activity until late-1977.
Live Web Chat
On Thursday, Jan. 20 from 3:00 to 4:00 EST, NASA planetary scientist Dr. Renee Weber will answer your questions about the inner workings of our nearest neighbor.
Joining the chat is easy! Simply return to this page http://www.nasa.gov/connect/chat/moon_core_chat.html a few minutes before 3:00 p.m. EST on Thursday, Jan. 20. The chat module will appear at the bottom of this page. After you log in, wait for the chat module to be activated, then ask your questions!
About Chat Expert Dr. Renee Weber
Dr. Renee Weber is a planetary scientist at NASA's Marshall Space Flight Center. She serves as the project scientist for the Lunar Mapping and Modeling Project, a software project designed to provide lunar maps and surface feature information to mission planners and other lunar researchers. Renee's scientific research focuses on planetary seismology, in particular the re-processing of seismic data from the Apollo missions. She is involved in several international efforts with goals of sending modern, broad-band seismometers to both the moon and Mars.
Marshall Space Flight Center, Huntsville, Ala.