Researchers exploring the surface magnetic field of Mars found that crustal field effects are very strong during the daytime but are almost negligible during the nighttime, with daytime crustal field effects being unaffected by season or Sun-Mars distance. Decoding the Martian crustal magnetic field and its effects on the near-Mars plasma environment is important for understanding magnetic shielding, which has a direct impact on future robotic/human missions to space.
Mars is a planet that does not have its own global magnetic field. However, crustal magnetic fields are scattered in the southern hemisphere of Mars. The crustal fields are located poleward of 30° South latitude (Southern Hemisphere) and within the region from 120° East to 240° East longitude.
Indian Institute of Geomagnetism (IIG), an autonomous institute of the Department of Science and Technology, whose scientists have long explored the Earth's magnetic field and its plasma environment, has expanded its focus areas to include the study of planetary space plasma. C Nayak, E Yijit, B Remya, J Bulusu, S Devanandan, S Singh and AP Dimri, P Padhye have extensively investigated how the weak crustal magnetic field of Mars controls its ionosphere and found that during the daytime, crustal magnetic fields strongly control the ionosphere in the southern hemisphere and such control is generally much stronger than in the northern hemisphere. However, during the nighttime, crustal magnetic fields lose their control over the ionosphere and hence the hemispheric asymmetry is lost.
Scientists observed that the daytime control of crustal magnetic fields on its ionosphere is independent of the Sun-Mars distance (seasons). The study was published in the Journal of Geophysical Research: Space Physics.
The study was conducted using nearly 8 years of in-situ data of electron density and magnetic field from the Mars Atmosphere and Volatile Evolution (MAVEN) satellite to investigate how crustal magnetic fields affect the Martian ionosphere. MAVEN is a NASA satellite orbiting Mars since around 2014.
This study by IIG scientists is a step towards increasing the knowledge that can help in future space missions.
Publication link: https://doi.org/10.1029/2024JA032760