Auroras From Space
Any planet that has an atmosphere has an aurora. The sun's solar wind flows out in all directions and thus hits all the planets. Atmospheres contain gas particles, and it is the particles that interact with the solar particles to create auroras.
A magnetic field is not necessarily needed for a planet to have an aurora. Venus has no magnetic field, so the particles from its atmosphere don't concentrate around any magentic poles and the auroras although the are irregular.
Some of the planets that have auroras include Jupiter, Saturn, Uranus and Neptune. Some moons are big enough that they have atmospheres so also have auroras such as Jupiter's moon Io. Here is a photo of Jupiter's auroras from both the south and north end.
Courtesy of the Hubble Site
This is a photo of Saturns auroras taken by the Hubble telescope. Scientists can determine the type of atmosphere planets have by examining the colors auroras emit since each gas has a specific color.
Courtesy of the Hubble Site
