卡西尼：土星探測器轉向，將完成它自我毀滅之路。聽吧

Cassini: Saturn probe turns towards its death plunge

卡西尼： 土星探測器轉向，將完成它自我毀滅之路

Methane rains out of Titan s orange sky

甲烷從泰坦的橘紅色天空如雨而降

The international Cassini spacecraft at Saturn has executed the course correction that will send it to destruction at the end of the week.

探測土星的卡西尼國際太空飛行器已經更改道，將在周末飛上毀滅之旅。

Cassini began its study of the ringed planet in 2004

卡西尼從2004年開始研究這個帶著光環的行星

The probe flew within 120,000km of the giant moon Titan on Monday - an encounter that bent its trajectory just enough to put it on a collision path with the ringed planet.

卡西尼探測器於星期一，擦著土星巨型月球泰坦的120,000km的距離飛過-這次的擦肩而過，把卡西尼送上了與這個帶著光環的行星正面衝撞的飛行軌道上。

Nothing can now stop the death plunge in Saturn s atmosphere on Friday.

這一來，什麼也不能阻擋它在本周五，將向土星大氣層發起的死亡衝擊。

Cassini will be torn to pieces as it heads down towards the clouds.

卡西尼將在一頭扎向土星的雲層時，被撕成碎片。

Its components will melt and be dispersed through the planet s gases.

探測器的部件將熔化並且通過行星的氣體煙消雲散。

Ever since it arrived at Saturn 13 years ago, the probe has used the gravity of Titan-the second biggest moon in the Solar System-to slingshot itself into different positions from which to study the planet and its stunning rings.

自從13年前，它到達土星之後,這個探測器就利用了泰坦的引力將自己彈射到不同的位置,以研究這個行星及其令人驚嘆的光環。泰坦是太陽系中第二大的衛星。

It has been a smart strategy because Cassini would otherwise have had to fire up its propulsion system and drain its fuel reserves every time it wanted to make a big change in direction.

這是一個明智之舉,否則卡西尼號也會在每次改變方向時消耗自己的燃料儲備來維持它的推進系統正常工作。

As it is, those propellants are almost exhausted and Nasa is determined the spacecraft will not be permitted to just drift around Saturn uncontrolled; it must be disposed of properly and fully.

儘管如此,那些推進劑也已經幾乎用盡了,並且美國航空航天局非常堅定表示，他們不會讓這個航天器失控地漂泊在土星附近，這個探測器必須得到完好的和充分的處理。

The agency called Monday s last encounter with Titan the "kiss goodbye」.

NASA稱Cassini周一的與泰坦的最後一次相遇就是「吻別"了。

"Cassini has been in a long-term relationship with Titan, with a new rendezvous nearly every month for more than a decade," said Earl Maize, the Cassini project manager at Nasa s Jet Propulsion Laboratory in Pasadena, California.

美國宇航局噴氣推進實驗室的卡西尼項目經理Earl Maize說：」卡西尼已經與泰坦已經相處很久了，十多年間，幾乎每個月都約會一次。。」

"This final encounter is something of a bittersweet goodbye, but as it has done throughout the mission, Titan s gravity is once again sending Cassini where we need it to go.」

「這最後的相遇是一種苦樂參半的告別，但正如這個任務所設定的那樣，泰坦的引力將再次將卡西尼送到我們需要它去的地方。

Closest approach to the moon s surface occurred at 19:04 GMT (20:04 BST; 15:04 EDT; 12:04 PDT).

與泰坦表面最接近的一刻是在19:04 GMT (20:04 BST; 15:04 EDT; 12:04 PDT)發生的。

As the probe passed Titan, it gathered some images and other science data that will be streamed back to Earth on Tuesday.

在探測器飛過泰坦的過程中，它收集了一些圖像和其他科學數據。這些信息將在星期二發回地球。

The investigation of the 5,150km-wide moon has been one of the outstanding successes of the Cassini mission.

對這個5,150公里寬的月球的調查是卡西尼號項目的傑出成就之一。

The spacecraft put a small robot called Huygens on its surface in 2005. It returned a remarkable image of rounded pebbles that had been smoothed by the action of flowing liquid methane. This hydrocarbon rains from Titan s orange sky and runs into huge seas at northern latitudes.

Cassini在2005年將一個叫做Huygens的小機器人放在泰坦的表面上。Huygens發回了一個非凡的圖像。圖像顯示在平滑的流動液體甲烷的影響下形成的圓形鵝卵石。這種碳氫化合物（甲烷）從泰坦的橙色天空中像雨似的落到表面,在北緯的區域形成海洋。

Cassini also spied what are presumed to be volcanoes that spew an icy slush and vast dunes made from a plastic-like sand.

卡西尼還偵察到了被認為是火山噴發的冰泥和由塑料般的沙子形成的巨大的沙丘。

Cassini scientist Michelle Dougherty from Imperial College London, UK, says there will be an effort in the days up to Friday to try to squeeze out every last scientific observation.

來自英國倫敦帝國理工學院的卡西尼號科學家Michelle Dougherty說,在星期五前到達之前的幾天里，我們將會盡一切可能的把每一個最後的科學觀察放進去。

"We re now running on fumes," she told BBC Radio 4 s Inside Science programme.

"我們在燃料上現在幾乎彈盡糧絕了,"她告訴BBC電台4的節目科學內幕。

"The fact that we ve got as far as we have, so close to the end of mission, is spectacular. We re almost there and it s going to be really sad watching it happen.」

"我們取得的這麼多的成就,我們這麼接近這個項目的尾聲,這本身已經非常了不起了。就快接近尾聲了,看著這個結局，我們會很傷心。

Besides a last look at Titan, scientists want to get a few more pictures of the rings and the moon Enceladus, before then configuring the spacecraft for its dramatic scuttling.

除了看泰坦最後一眼,科學家們還想再多拍一些光環和恩塞拉都斯（土衛二）的照片。在這之後，他們會設定這個太空船的戲劇性的自我毀滅。

The idea is to use only those instruments at the end that can sense Saturn s near-space environment, such as its magnetic field, or can sample the composition of its gases.

現在的計劃是在尾聲之際，只使用的那些能探測土星近空間環境的儀器，比如它的磁場,或者可以對它的氣體成分進行取樣。

In the final three hours or so before "impact" on Friday, all data acquired by the spacecraft will be relayed straight to Earth, bypassing the onboard solid state memory.

在星期五的"撞擊"之前的最後三小時左右，航天器所獲得的所有數據都將跳過機載固態存儲器，直接傳送到地球。

Contact with the probe after it has entered the atmosphere will be short, measured perhaps in a few tens of seconds.

Cassini一旦進入大氣層，（地球）和Cassini的接觸將是短暫的,也許是幾十秒。

The signal at Earth is expected to drop off around 11:55 GMT (12:55 BST; 07:55 EDT; 04:55 PDT). Engineers will be able to be more precise once they have looked at the position of the probe after Monday s change in course.

在地球上的信號失聯將是大約11:55 GMT (12:55 BST; 07:55 EDT; 04:55 PDT)。工程師在星期一探測器位置調整之後觀察之後將會更精確（判斷預計的失聯事件）。

"The Cassini mission has taught us so very much, and to me personally I find great comfort from the fact that Cassini will continue teaching us right up to the very last seconds," said Curt Niebur, the Cassini programme scientist at Nasa Headquarters in Washington, DC.

「卡西尼號使命教會了我們很多，對我個人來說，卡西尼號直到它的最後幾秒鐘都將繼續指導著我們，這讓我感到非常欣慰,"駐華盛頓特區的美國宇航局總部的卡西尼計劃科學家Curt Niebur說。

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