Since magnetic anomalies on Mars were detected in Noachian-aged crust (about 4.4 billion years old) by the Mars Global Surveyor mission in the 1990s, scientists have been searching for their mineral origins. So far, meteorite samples from Mars have not yielded rocks with enough magnetic minerals to account for the anomalies.
Gattecceca et al. present new findings from sample NWA 7034, which they note has “a unique magnetic mineralogy.” Using multiple instruments to analyze the magnetic and physical properties of the Martian sample, the authors found abundant magnetic minerals, including maghemite and goethite, two minerals that form during near-surface hydrothermalism.
Other characteristics suggest that the sample most likely originated in the Noachian crust, lending credence to the idea that the minerals may be responsible for Mars’s magnetic anomalies. The authors suggest that investigating regions of similar lithology on Mars will help in the study of the planet’s magnetic field, which will lead to a better understanding of the planet’s evolution. (Geophysical Research Letters, doi:10.1002/2014GL060464)
—JoAnna Wendel, Staff Writer