理工類考試輔導：補全對話Image Martian Dust

　　NASAs Phoenix Mars Lander1 has taken its first-ever picture of a single particle of rusty Martian dust with one of its microscopes. The dust particles of dust were shown at a higher magnification than anything outside of Earth that has been imaged before. The rounded particle measured only about one micrometer， or one millionth of a meter， across.

　　Taking this image required the highest resolution microscope operated off Earth2 and a specially designed device to hold the Martian dust，" said Tom Pike， a Phoenix science team member from Imperial College London3. "We always knew it was going to be technically very challenging to image particles this small4.

　　The device that imaged the dust speck is called an atomic force microscope， which maps the shape of particles in three dimensions by scanning them with a sharp tip at the end of a spring. The atomic force microscope can detail the shapes of particles as small as about 100 nanometers. And this wont be the last dust particle that Phoenix will image5. "After this first success， were now working on building up a portrait gallery6 of the dust on Mars，" Pike said.

　　Dust exists everywhere on Mars， coating the surface and giving it its rusty red color. Dust particles also color the Martian sky pink and feed storms that regularly envelope the planet. The ultra-fine7 dust is the medium that actively links gases in the Martian atmosphere to processes in Martian soil， so it is critically important to understanding Mars environment8， the researchers said.

　　The $420-million Phoenix mission is analyzing the dust and subsurface ice layers of Mars arctic regions to look for signs of potential past habitability. The particle seen in the atomic force microscope image was part of a sample scooped by the robotic arm from the "Snow White" trench and delivered to Phoenixs microscope station in early July.

　　詞匯：

　　image v. 繪……的圖像 scan v. 掃描

　　magnification n. 放大 subsurface adj. 地面下的

　　micrometer n. 微米 habitability n. 居住性

　　resolution n. 分辨率，清晰度 scoop v. 挖

　　map v. 繪制……的地圖 trench n. 溝

　　注釋：

　　1. NASAs Phoenix Mars Lander： 美國國家航空航天局的鳳凰號火星登陸器

　　2. off earth ： 地球之外

　　3. Imperial College London ： 倫敦帝國學院

　　4. image particles this small： 描繪如此之小的微粒。image particles this small是口語的說法，其意思是image such small particles/image particles which are so small.

　　5. And this wont be the last dust particle that Phoenix will image： 這不會是鳳凰號掃描圖像的最后的塵粒。本句的言外之意是：科學家將會收集更多的火星微粒進行掃描。

　　6. portrait gallery： (火星塵粒)圖像陳列館

　　7. ultra-fine：超小的

　　8. it is critically important to understanding Mars environment： 火星塵粒對于了解火星環境是極端重要的。it指代上一句的dust，而to是介詞，所以后接動名詞 understanding.

　　練習：

　　1. The dust particle on Mars is the smallest particle that has been imaged outside of Earth.

　　A. Right B. Wrong C. Not mentioned