Remote sensing of the polar aurora and ionospheric convection is used to characterize the interaction between the solar wind and the Earth magnetosphere during steady magnetospheric convection (SMC) intervals and compare them with other previously studied geomagnetic conditions. It is found that the Earth magnetosphere may exhibit four different coupling modes ordered by increasing open magnetic flux and magnetic reconnection rate: quiet times, SMC, substorm and sawtooth events.

Early models of the main auroral emission at Jupiter assumed axisymmetry, but significant local time variability is obvious on any image of the Jovian aurorae. Here we use far-UV images from the Hubble Space Telescope to further characterize these variations on a statistical basis. We show that the dusk side sector is ~3 times brighter than the dawn side, and we suggest that such an asymmetry could be the result of a partial ring current in the nightside magnetosphere.