The possibility that life once existed on Mars has been strengthened by the discovery that water was plentiful on the planet some 4bn years ago and that conditions were conducive to the survival of micro-organisms.

“It wasn't this hot, boiling cauldron,” says John Mustard. “It was a benign, water-rich environment for a very long period of time.”

Prof Mustard and his colleagues at Brown University, Rhode Island, and 13 other institutions made their discoveries using an instrument on the Mars Reconnaissance Orbiter spacecraft, which could detect clay-like minerals called phyllosilicates. These have the unusual property of preserving a record of the way water interacts with rocks. Writing in this week's Nature magazine, the scientists argue that water was present 4km-5km below the ancient Martian surface and elsewhere.

科学家发现，大约40亿年前火星上曾存在大量的水，同时环境有利于微生物的存活，由此，火星上曾存在生命的可能性有所加大。

约翰?马斯塔德(John Mustard)教授表示：“火星那时可并不像蒸锅那么热，很长一段时期它都气候温和并且富含水分。”

这一发现是马斯塔德和他在罗德岛布朗大学(Brown University)及其它13个机构的同事，通过“火星勘测轨道飞行器”(Mars Reconnaissance Orbiter)上的设备完成的。该设备可探测到页硅酸盐(Phyllosilicate)，一种黏土状的矿物质。这些矿物质具有非同寻常的特性：保存水与岩石相互反应的记录。这些科学家在本周《科学》(Nature)杂志上撰文称，古代火星表面以下4至5公里处及其它地方曾有水存在。