Mars is dry today, but numerous precipitation-fed paleo-rivers are found across the planet’s surface. These rivers’ existence is a challenge to models of planetary climate evolution. We report results indicating that, for a given catchment area, rivers on Mars were wider than rivers on Earth today. We use the scale (width and wavelength) of Mars paleo-rivers as a proxy for past runoff production. Using multiple methods, we infer that intense runoff production of >(3–20) kg/m2 per day persisted until <3 billion years (Ga) ago and probably <1 Ga ago, and was globally distributed. Therefore, the intense runoff production inferred from the results of the Mars Science Laboratory rover was not a short-lived or local anomaly. Rather, precipitation-fed runoff production was globally distributed, was intense, and persisted intermittently over >1 Ga. Our improved history of Mars’ river runoff places new constraints on the unknown mechanism that caused wet climates on Mars.
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机译：今天的火星是干燥的，但是在整个地球表面发现了许多由降水喂养的古河。这些河流的存在对行星气候演化模型提出了挑战。我们报告的结果表明，对于给定的集水区，火星上的河流要比当今地球上的河流宽。我们使用火星古河的规模（宽度和波长）作为过去径流生产的代表。使用多种方法，我们推断每天>（3–20）kg / m 2 的密集径流生产持续到<30亿年（Ga）之前，可能<1 Ga之前，并且在全球范围内分散式。因此，由火星科学实验室流浪者的结果推断出的强烈径流产生并不是短暂的或局部的异常。相反，以降水为基础的径流生产是全球性分布的，强度很高，并在> 1 Ga以上时断断续续地持续。我们改善的火星河径流历史为未知的机制造成了新的限制，这种未知的机制导致了火星上出现了潮湿的气候。
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