( ) A cosmic-ray proton in interstellar space has an energy of 14.5 MeV and executes a circular orbit having a radius equal to that of Mars' orbit around the Sun (2.28 x 101 m). What is the magnetic field (in T) in that region of space? 2.41e-12 T (b) What If? The cosmic ray proton enters our solar system where the interplanetary magnetic field has a magnitude of 5.00 nT and is perpendicular to the velocity of the proton. What is the radius (in m) of the proton's circular orbit in this field? m