A cosmic ray proton in interstellar space has a kinetic energy of 10.0 MeV and maintains a circular orbit having a radius equal to that of Mercury's orbit around the sun, which is 5.80 x 10^10 m. What is the magnetic field in that region of space? ( 1eV= 1.60 x 10^-19 J, and mp= 1.67 x10^-27 kg)