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Magnetometer (MAG)

NSSDC ID: 1989-084B-03
Mission Name: Galileo Orbiter
Principal Investigator: Dr. Margaret Galland Kivelson


The magnetometer (MAG) on Galileo was used to: (1) map the configuration of the Jovian magnetosphere and analyze its dynamics; (2) examine magnetospheric-ionospheric coupling; (3) measure fluctuations in the ambient magnetic field; (4) determine whether the Galilean satellites have intrinsic magnetic fields; and, (5) investigate the nature of the magnetosphere's interaction with the satellites. In addition to these primary goals, the magnetometer was also used to make extensive studies of the interplanetary medium, the solar wind interaction with the asteroids Gaspra and Ida, and the Earth's magnetosphere.

The system consisted of two triaxial fluxgate magnetometers, one placed at the end of a boom 11.03 m from the spacecraft spin axis, the other on the same boom but at a distance of 6.87 m from the spin axis. This dual magnetometer configuration, used to provide a real-time estimate of the spacecraft-generated magnetic field as well as providing redundancy in the in situ measurements, was similar to that of instruments used on other missions (e.g., Voyager). The outboard sensors had dynamic ranges of +/-32 nT and +/-512 nT while those of the inboard sensors were +/-512 nT and +/-16,384 nT. This limitation to two ranges for each magnetometer assembly optimized the design to achieve low noise levels and small offsets. In addition, the lower range of the outboard sensors was designed for solar wind and distant Jovian magnetotail measurements whereas the higher range of the inboard sensor was intended for the inner Jovian magnetosphere.

Calibrations for the instrument were performed in-flight using a calibration coil which generated a known magnetic field at a set frequency, thus permitting the signal to be identified even when the ambient field was not entirely quiet. This calibration method also permitted the orientation of the sensors to be well determined.

Alternate Names

  • MAG

Facts in Brief

Mass: 7.0 kg
Power (avg): 3.9 W
Bit rate (avg): 0.24 bps

Funding Agency

  • NASA-Office of Space Science Applications (United States)


  • Planetary Science: Fields and Particles
  • Space Physics: Heliospheric Studies

Additional Information

Questions or comments about this experiment can be directed to: Dr. Edwin V. Bell, II.



NameRoleOriginal AffiliationE-mail
Prof. Robert L. McPherronCo-InvestigatorUniversity of California, Los
Dr. David J. SouthwoodCo-InvestigatorImperial
Dr. Raymond J. WalkerCo-InvestigatorUniversity of California, Los
Prof. Charles F. KennelCo-InvestigatorUniversity of California, Los
Prof. Paul J. Coleman, Jr.Co-InvestigatorUniversity of California, Los Angeles 
Dr. Margaret Galland KivelsonGeneral ContactUniversity of California, Los
Dr. Christopher T. RussellCo-InvestigatorUniversity of California, Los

Selected References

Kivelson, M. G., et al., Magnetic field studies of the solar wind interaction with Venus from the Galileo flyby, Science, 253, No. 5027, 1518-1522, Sep. 1991.

Kivelson, M. G., et al., The Galileo magnetic field investigation, Space Sci. Rev., 60, No. 1/4, 357-383, May 1992.

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