Calculateur d'Intensité du Champ Magnétique Planétaire
Calculez l'intensité du champ magnétique d'une planète.
Surface Magnetic Field (equator)
0.00003070 T
Surface Magnetic Field (equator) vs Magnetic Dipole Moment
Formule
## Planetary Magnetic Field A planet's magnetic field can be approximated as a dipole near the surface. ### Equatorial Field **B_eq = (mu0 / 4pi) * M / R cubed** where mu0/(4pi) = 1e-7 T m/A. ### Polar Field **B_pole = 2 * B_eq** Earth's dipole moment is about 7.94 x 10^22 A m2, giving an equatorial field of roughly 3 x 10^-5 T (0.3 Gauss).
Exemple Résolu
Earth: dipole moment = 7.94e22 A m2, radius = 6.371e6 m.
- 01B_eq = 1e-7 * M / R cubed
- 02R cubed = (6.371e6)^3 = 2.586e20
- 03B_eq = 1e-7 * 7.94e22 / 2.586e20
- 04B_eq = 3.07e-5 T = 0.307 Gauss
Questions Fréquentes
What generates a planet's magnetic field?
Convective motion of electrically conducting fluid (molten iron in Earth's outer core) produces a self-sustaining dynamo.
Which planet has the strongest magnetic field?
Jupiter, with a dipole moment about 20 000 times Earth's, giving a surface field of about 4 Gauss.
Why is a magnetic field important for life?
It deflects the solar wind and cosmic rays, protecting the atmosphere from erosion and the surface from harmful radiation.