在远古时代,火星可能拥有许多微生物生命在其表面繁衍生息的必要成分。
现在,美国宇航局的毅力号探测器的新发现显示了三重令人信服的证据——包括水、有机化合物和化学能源的存在——所有这些都在位于杰泽罗陨石坑的一块岩石上。
虽然这是迄今为止火星上存在微生物生命的最佳线索,但仍有其他解释可以在没有微生物存在的情况下解释这种地质现象。
“火星上有生命吗”这个问题让天体生物学家和大卫·鲍伊都感到困惑。后者想象着红色星球上有一些可怕的蜘蛛群,而美国宇航局的科学家们则专注于寻找微生物生命曾经在这颗距离太阳第四远的岩石上繁衍生息的证据。事实上,美国宇航局已经花费了 50 多亿美元,将两辆极其复杂的机器人探测器——好奇号和毅力号——送上火星表面,以实现这一特定的微生物任务。
Now, one of those rovers might’ve discovered one of the most compelling pieces of evidence for Martian microbial life. Located on an arrowhead-shaped, three-foot-long rock nicknamed “Cheyava Falls” in the Jezero Crater (the 28-mile-wide crater that Perseverance has called home for the past three years), this “piece of evidence” is actually a trifecta of data points that suggest the presence of past microbial life. The rock in question features two vertical veins of calcium sulfate that likely formed from past water, and these stripes both flank a red band of rock filled with “leopard spots.”
NASA has discovered evidence of past water on Mars before, but it’s this narrow band of rock that brings new meaning to this discovery. Using its SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) and PIXL (Planetary Instrument for X-Ray Lithochemistry) instruments, Perseverance determined the existence of organic compounds within the rock. Oh, and those “leopard spots?” Those likely indicate chemical reactions that could’ve supplied energy to ancient microbial Martians.