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. 

    科學家發現，大約40億年前火星上曾存在大量的水，同時環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。

    約翰•馬斯塔德(John Mustard)教授表示：“火星那時可并不像蒸鍋那么熱，很長一段時期它都氣候溫和并且富含水分。”

    這一發現是馬斯塔德和他在羅德島布朗大學(Brown University)及其它13個機構的同事，通過“火星勘測軌道飛行器”(Mars Reconnaissance Orbiter)上的設備完成的。該設備可探測到頁硅酸鹽(Phyllosilicate)，一種黏土狀的礦物質。這些礦物質具有非同尋常的特性：保存水與巖石相互反應的記錄。這些科學家在本周《科學》(Nature)雜志上撰文稱，古代火星表面以下4至5公里處及其它地方曾有水存在。