美國宇航局：火星上存在液態水

Scientists at the U.S. space agency say that they have detected salty water streams appearing during summer on Mars. The finding supports the notion there may be life on the red planet.

Scientists have long known that there once was water on Mars. But they thought a change in climate had caused the planet to become aRid. On Monday, NASA scientists announced they have evidence that there is more water on the red planet than previously thought.

Jim Green, NASA Director of Planetary Science, said, "Our rovers are finding that there is a lot more humidity in the air than we ever imagined. As we ingest the soils, they are moist, they're hydrated, full of water."

For several years scientists have monitored mysterious streaks on the slopes of Mars that appear to be waxing and waning. A comprehensive analysis of the data collected by NASA rovers reveals that the darker streaks showing up in the summer are most likely streams of water.

Michael Meyer, of NASA Mars Exploration, said, "But we don't know where the water actually comes from and so it could be hiding a major source of water in the subsurface. But we don't have any idea and so this is sort of the next puzzle to this recent discovery."

The answer to this and many other questions will be clearer in about five years, when the next big NASA rover brings back samples from Mars. The existence of water would indicate that there are living organisms on the planet.

It would also facilitate future space travel.

John Grunsfeld, NASA head of science, said, "When you have water ... you know, what's water? Hydrogen and Oxygen. That's what we make rocket fuel out of."

John Grunsfeld, NASA head of science, said, "From the Curiosity rover we now know that Mars once was a planet very much like earth, with warm salty seas, with fresh water lakes, probably snow kept peeks and clouds and a water cycle, just like we are studying here on earth with our earth science satellites, the water cycle here on earth. But something has happened to Mars and it lost its water, but we still have in the atmosphere and on the surface for the most part, but we still have the question, did life arise on Mars once and can we find out?"

The NASA announcement comes within days of the release of a new movie, The Martian, featuring Matt Damon as an astronaut stuck on Mars. Scott Ridley's science-fiction film, based on a best-selling book, is sure to increase curiosity about the planet.美國宇航局的科學家說，他們探測到火星夏季出現“滷水流”。這一發現支持這個紅色行星上可能有生命的觀點。

科學家早就知道，火星上曾經有水。但是他們認爲，氣候變化已導致這顆行星無水。美國航空航天局的科學家星期一宣佈，他們掌握的證據顯示，這顆紅色行星上的水比以前所認爲的多。

美國宇航局天體科學部主任吉姆·格林說：“我們的探測車發現，那裏的空氣溼度比我們原先想象的高。土壤攝取後，變潮變溼，充滿水份。”

連續幾年，科學家觀察到火星坡地上有看似彎彎曲曲的神祕條痕。對航空航天局探測車採集數據的全面分析表明，夏季出現的色澤較暗條痕，極有可能是一道道水流。

航空航天局火星探測部的邁克爾·邁耶說：“不過我們並不知道水到底來自何方，可能是地表之下隱藏着一個大水源，但是對此我們還一無所知，因此對這項最新發現而言，這是下一個謎團。”

五年後, 航空航天局的下一個大探測車將從火星帶回樣本時，有關這個問題以及其他問題的答案大約將會比較清楚。水的存在將表明，那個行星上有生命。

這將有助於未來的宇宙旅行。對此美國宇航局天科學部負責人約翰·格倫斯菲爾德說：“有水，大家知道，水是什麼？就是氫氧化合物，是我們製造火箭燃料的物質。”

格倫斯菲爾德說：“藉助‘好奇’號探測車，我們如今知道，火星曾是一個酷似地球的行星，有過溫暖的鹹海，淡水湖，或許還有白雪覆蓋的山峯，雲朵和水的循環。就像我們在地球上用地球科學衛星對水的循環做研究一樣。不過，火星後來發生了情況，致使其水的喪失，不過火星大氣和地表大部依然還存有水，只是我們依然還有疑問，火星上曾有生命出現嗎？我們能夠找到嗎？”

航空航天局宣佈上述消息前幾天，新電影《火星人》發行，影片講述了由馬特·戴蒙扮演的宇航員在火星上陷入困境的故事。斯科特·裏德利依據一部暢銷書改編的這部科幻片，肯定會增加人們對這個行星的好奇之心。