The magnetic field of Mars is measured on a large scale by orbiting spacecraft and on a very small scale by Martian meteorites. Magnetic probes examine crustal magnetism on length scales comparable to distance or height from the source.
During the Zhurong rover’s initial 1-km journey to Mars, a joint research team led by Professor DU Aim from the Institute of Geography and Geophysics of the Chinese Academy of Sciences (IGGCAS) detected incredibly weak magnetic fields. This suggests that there are no magnetic features below Jurong’s landing area.
Scientists used two Fluxgate magnetometers aboard the Jurong rover to conduct the first magnetic field survey of the Utopia basin on the surface of Mars. In the Utopia Basin, the magnetic field strength was shockingly weak.
The crustal magnetic field at InSight’s landing site was stronger than that obtained from orbital observations, according to data from the NASA Mars lander InSight, which landed about 2,000 km southeast of Jurong. Jurong’s measurements, however, showed the opposite effect, with the mean intensity being an order of magnitude lower than that subtracted from the orbit.
One of the biggest challenges in planetary exploration is obtaining highly accurate planetary surface magnetic data. Zhurong was the first rover to use magnetometers. The orbit calibration used rover and mast rotations to isolate the Martian magnetic field from the rover interference field. The surface of Mars can now be measured in situ at multiple points with an accuracy of the order of nanoteslas.
Fragile magnetic fields detected by Jurong suggest that the crust beneath the Utopia Basin may have been magnetized by a significant impact in the early Hesperian, or it may have remained unmagnetized since its formation about 4 billion years ago. Additional insight into the interrelated magnetic, climatic, and internal history of Mars is provided by this new limitation on the timeline of the Martian dynamo.
Journal Note:
- Du, A., Ji, Y., Wang, H. and many others. A ground magnetic probe on Mars from the Jurong rover. Natural Astronomy (2023). DOI: 10.1038/s41550-023-02008-7