The Magnetic Anomalies of Mars

The Magnetic Anomalies found by the MAG/ER experiment on the Mars Global Surveyor spacecraft are inconveniently bisected by the 180° Longitude line, and so appear at both ends of the standard Mars Mercator Projection.
Here, the MAG/ER team have made hemispheric projections centered on the area of strongest anomalies.
The 3 hemispheres show the 3 components of the Magnetic Field: B(r) is the Radial Field, which is perpendicular to Mars' Surface; B(Θ) is the Polar Field, oriented along lines of Longitude; and B(Φ) is the Circumferential Field, oriented along lines of Latitude.