The MESSENGER spacecraft has been in orbit around Mercury since March 2011. Magnetic field measurements taken by MESSENGER have yielded definitive evidence for a weak dipolar internal field, generated by dynamo action in Mercury’s core. The weak field, together with Mercury’s proximity to the sun, mean that Mercury’s magnetosphere is small and highly dynamic, responding to changes in solar wind conditions on time scales of seconds to a Mercury year. Why is Mercury’s field so weak? What is the history of the planet’s magnetic field? How and when can solar wind plasma enter the magnetosphere and even reach Mercury’s surface and what are the consequences? In this talk I will review results from MESSENGER that shed light on the planet’s magnetic field and indicate that Mercury’s deep interior, surface and space environment are intimately coupled.
Published on March 4, 2013