Uranus DOES have a magnetic field.
More Info: Uranus does have a magnetic field, but the properties of the field are not consistent with the magnetic field of the Earth. Comparatively, the magnetic field of Earth is fundamentally centered on the planet and connected to the planet tilt.
The Uranus Magnetic Field
Uranus is one of the Jovian planets, or giant planets. It is an ice planet, and the composition of the planet can have a direct impact on the magnetic field and the degree of tilt. For comparison, the magnetic and rotational axis for Earth is 11 degrees as compared to Uranus at nearly 60 degrees. [“Uranus/Neptune.” The Electronic Universe]
The Impact of the Magnetic Field
This differential indicates that the rotation of Uranus is considerably different from the Earth. The magnetic field of Uranus has been found to be particularly strong, but may be unstable because of the extreme pole shift. Scientists think that the center of the planet is rich in methane and ammonia. Ammonia is a superb electrical conductor, creating a large amount of atoms without electrons. [“The Ice Giants Uranus & Neptune.” Astronomy Ohio State]
How the Magnetic Field is Affected
Ammonia and hydrogen levels indicate that this large number of free ions in the mantle can form a collective conductive ionic layer. The result of this layer can be a stronger magnetic field, though the magnetic field is not centered. The large tilt affects particle density in the atmosphere, because it allows for more solar wind activity in the planetary radiation belts. Additionally, the offset of the magnetic field can affect field variance at the cloud level of the atmosphere by a factor of five to ten, depending on longitude and latitude positioning around Uranus. [“Uranus’s Magnetic Field.” Jrank]
“Uranus/Neptune.” The Electronic Universe. N.p., n.d. Web. 16 Jan. 2013. <http://zebu.uoregon.edu/disted/ph121/js21.html>.
“The Ice Giants Uranus & Neptune.” Astronomy Ohio State. N.p., n.d. Web. 16 Jan. 2013. <http://www.astronomy.ohio-state.edu/~pogge/Ast161/Unit6/uranep.html>.
Uranus’s Magnetic Field.” Jrank. N.p., n.d. Web. 16 Jan. 2013. <http://science.jrank.org/pages/7118/Uranus-Uranus-s-magnetic-field.html>.
Nov 18: Uranus/Neptune.” Nov 18: Uranus/Neptune. N.p., n.d. Web. 16 Jan. 2013. <http://zebu.uoregon.edu/disted/ph121/js21.html>.