Hello!
Some of the other planets have strong magnetic fields, just like the Earth does. Venus and Mars do not have strong, global magnetic fields. Mars only has weak remnants of a magnetic field in rocks that were formed long ago when Mars may have had a much stronger, global magnetic field. It is kind of interesting to note that while Mercury does not have an atmosphere like the other Terrestrial planets, it does have a strong magnetic field. The lack of an atmosphere and the proximity of Mercury to the Sun means that the interaction of its magnetosphere with the solar wind may be very different from the interaction between Earth's magnetosphere and the solar wind. This is one of the things being investigated by MESSENGER, which is the spacecraft first to orbit Mercury. Jupiter has a very strong magnetic field and very intense radiation belts. One of Jupiter's moons, Ganymede, also has a strong magnetic field and its own magnetosphere. If I remember correctly, Ganymede is the only moon in the Solar System to have its own magnetosphere. Although the solar wind does affect Jupiter's magnetosphere, the dynamics of Jupiter's magnetosphere are affected more strongly by the volcanoes on Jupiter's moon Io, which create a feature called the Io plasma torus inside Jupiter's magnetosphere. Saturn, Uranus, and Neptune also have magnetic fields. Aurora have been observed on Jupiter, Saturn, Uranus, and Neptune.
Kris