The solar wind is a thin, hot gas given off by the sun. Charged particles in this gas enter the magnetic field of the earth and can experience a magnetic force. Suppose a charged particle traveling with a speed of 8.84E+6 m/s encounters the earth's magnetic field at an altitude where the field has a magnitude of 1.23E-7 T. Assuming that the particle's velocity is perpendicular to the magnetic field, calculate the radius of the circular path on which the particle would move if it were an electron.