近日，美国国家航空航天局约翰逊航天中心Tanya S. Peretyazhko团队揭示了赤铁矿是火星上古代气候变化的矿物学标志。该项研究成果发表在2026年5月28日出版的《科学》杂志上。

火星的古代气候经历了从温暖到寒冷的地表条件转变。这一气候转型已有地貌学证据支持，但缺乏合适的矿物学指示标志。

研究组利用好奇号火星车在盖尔陨石坑内测得的赤铁矿（氧化铁）晶体学性质，并与实验室实验进行了对比。在好奇号所探测的最古老沉积岩（默里组）中，赤铁矿微晶尺寸约为5至65纳米；而在上覆的较年轻地层（米拉多组和卡罗琳·舒梅克组）中，则小于10纳米。研究组将默里组中较大的微晶归因于温暖湿润条件下地下水作用导致的沉积后粗化，该过程持续了数百万年。在上覆地层中，小尺寸微晶的赤铁矿与针铁矿（羟基氧化铁）共生，这与更寒冷且水资源受限的条件相一致。

附：英文原文

Title: Hematite is a mineralogical marker of ancient climate change on Mars

Author: Marek Szczerba, Tanya S. Peretyazhko, Elizabeth B. Rampe, Thomas F. Bristow, Benjamin M. Tutolo, Douglas W. Ming, David T. Vaniman, Richard V. Morris, Silas J. Ralston, Nikole C. Haney, Bum Soo Kim, David F. Blake, Steve J. Chipera, Robert T. Downs, Robert M. Hazen, Shaunna M. Morrison, Allan H. Treiman, Albert S. Yen, Valerie M. Tu, Michael T. Thorpe, Cherie N. Achilles, David J. Des Marais, John P. Grotzinger, Nicholas Castle, Patricia C. Craig, Elisabeth M. Hausrath, Sarah L. Simpson

Issue&Volume: 2026-05-28

Abstract: The ancient climate of Mars changed from warm to cold surface conditions. This climate transition is demonstrated by geomorphological evidence but lacks suitable mineralogical indicators. We investigated the crystallographic properties of hematite (iron oxide) in Gale crater measured by the Curiosity rover and compared them with laboratory experiments. Hematite crystallite sizes are about 5 to 65 nm in the oldest sedimentary rocks investigated by the rover (the Murray formation) and less than 10 nm in the younger overlying strata (the Mirador and Carolyn Shoemaker formations). We attribute the larger crystallites in the Murray formation to postdepositional coarsening by groundwater in warm and wet conditions that persisted for several million years. Hematite with small crystallites co-occurs with goethite (iron oxyhydroxide) in the overlying layers, consistent with colder and water-limited conditions.

DOI: adv5447

Source: https://www.science.org/doi/10.1126/science.adv5447