Probing the Solar Magnetic Field with a Sun-Grazing Comet

Abstract
A Comet in the Sun: In 2011, comet Lovejoy plunged into the solar atmosphere and survived its flight through a region of the Sun that has never been visited by spacecraft. Downs et al. (p. 1196 ) used spacecraft observations of this Sun-grazing comet, combined with advanced magnetohydrodynamic simulations, to constrain the magnetic field of the solar atmosphere—a quantity that has been very difficult to measure directly.