Jupiter’s auroras have an added twist that is not seen on Earth, however. As Jupiter’s magnetic field sweeps past Io, it generates an electric potential of 400,000 volts (V). This potential accelerates electrons, causing them to spiral along Jupiter’s magnetic-field lines. The result is a magnetic channel, called a flux tube, that connects Io with Jupiter’s atmosphere near the planet’s magnetic poles (Figure 10.23). Io’s flux tube carries power roughly equivalent to the total power produced by all electrical generating stations on Earth. Much of the power generated within the flux tube is radiated away as radio energy. These radio signals are received at Earth as intense bursts of synchrotron radiation. However, a substantial fraction of the energy of particles in the flux tube is also deposited into Jupiter’s atmosphere. At the very location where Io’s flux tube intercepts Jupiter’s atmosphere, there is a spot of intense auroral activity. As Jupiter rotates, this spot leaves behind an auroral trail in Jupiter’s atmosphere. The footprint of Io’s plasma torus, along with its wake, can be seen outside the main auroral ring in Figure 10.22a.