Department of Earth and Planetary Sciences. Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA, USA.
Nat Commun. 2021 Mar 19;12(1):1754. doi: 10.1038/s41467-021-21762-8.
Long-lived hydrothermal systems are prime targets for astrobiological exploration on Mars. Unlike magmatic or impact settings, radiogenic hydrothermal systems can survive for >100 million years because of the Ga half-lives of key radioactive elements (e.g., U, Th, and K), but remain unknown on Mars. Here, we use geochemistry, gravity, topography data, and numerical models to find potential radiogenic hydrothermal systems on Mars. We show that the Eridania region, which once contained a vast inland sea, possibly exceeding the combined volume of all other Martian surface water, could have readily hosted a radiogenic hydrothermal system. Thus, radiogenic hydrothermalism in Eridania could have sustained clement conditions for life far longer than most other habitable sites on Mars. Water radiolysis by radiogenic heat could have produced H, a key electron donor for microbial life. Furthermore, hydrothermal circulation may help explain the region's high crustal magnetic field and gravity anomaly.
长寿的热液系统是火星天体生物学探索的主要目标。与岩浆或撞击环境不同，放射性热液系统可以存活超过 1 亿年，因为关键放射性元素（如 U、Th 和 K）的 Ga 半衰期长，但在火星上仍未被发现。在这里，我们使用地球化学、重力、地形数据和数值模型来寻找火星上潜在的放射性热液系统。我们表明，曾经拥有一个巨大内陆海的 Eridania 地区，其水量可能超过所有其他火星地表水的总和，可能很容易容纳一个放射性热液系统。因此，Eridania 地区的放射性热液作用可能为生命维持了比火星上大多数其他宜居地点更长时间的宜人条件。放射性热产生的水的辐射分解可能产生了 H，这是微生物生命的关键电子供体。此外，热液循环可能有助于解释该地区高的地壳磁场和重力异常。
