火星上有"樹"? 有圖有真相
Nasa photographs 'trees' on Mars
美國國家航空航天局從火星上拍到“樹木”
The images appear to show rows of dark "conifers" sprouting from dunes and hills on the planet surface. But the scene is actually an optical illusion.
從圖片中我們可以看出，成排的“針葉林”從火星表面的沙丘和小山上長出。而事實上，這樣的場景只是一種光學錯覺。
The photographs actually show sand dunes coated with a thin layer of frozen carbon dioxide, or dry ice, less than 240 miles from the planet's north pole.
這張圖片實際顯示的，是距離火星北極不足240英里的沙丘上覆蓋的一層薄薄的冰凍二氧化碳、或乾冰。
The "trees" are really trails of debris caused by landslides as ice melts in Mars's spring. You can even see a cloud of dust, just to the left of centre of the picture, where an avalanche is caught happening.
這些“樹木”的真實面孔是火星春天冰層融化時造成山崩、從而產生的碎片痕跡。你甚至可以從圖片正中偏左的位置上、看到一場被抓拍到的雪崩，那裏有一團塵霧。
The photograph was taken from orbit around Mars by HiRISE, the most powerful camera sent to another planet.
這張圖片是由環繞火星軌道衛星上的HiRISE拍到，這是我們派往火星最強大的照相機。
NASA's Candy Hansen told The Sun: "The streaks are sand, dislodged as ice evaporates, which slide down the dune. At this time of the Martian year the whole scene is covered by CO2 frost."
美國國家航空航天局的Candy Hansen告訴記者：“這些紋路是沙子，在冰層蒸發的時候發生了位置偏移，從而滑下了沙丘。在火星的這個季節裏，整個星球都被二氧化碳的迷霧覆蓋。”
Last month Nasa announced a new telescope had detected five planets outside the solar system. The observatory, which was launched last year to find other Earths, made the discoveries in its first few weeks of science operations.
上個月，美國國家航空航天局宣佈他們的新望遠鏡發現了太陽系外的五個星球。該觀測臺去年在剛開始科學探測的幾個星期內，就曾宣佈他們發現了另一個地球
Although the new worlds, called exoplanets, are all bigger than Neptune, Nasa said their discovery showed that the planet hunting telescope was working well.
儘管這些被發現的新外部行星都比海王星要大，美國國家航空航天局仍表示，他們的望遠鏡在探測行星時運行良好。
