NASA"s Phoenix Mars Lander 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 Earth and a specially designed device to hold the Martian dust," said Tom Pike, a Phoenix science team member from Imperial College London. "We always knew it was going to be technically very challenging to image particles this small."
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 won"t be the last dust particle that Phoenix will image. "After this first success, we"re now working on building up a portrait gallery 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 ultrafine 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" environment, 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 Phoenix"s microscope station in early July.
单选题
The dust particle on Mars is the smallest particle that has been imaged outside of Earth.
【正确答案】
A
【答案解析】[解析] 题意：火星微粒是在地球外观测到的最小的颗粒。
根据文章第一段第二句“The dust particles of dust were shown at a higher magnification than anything outside of Earth that has been imaged before.”可知在地球外，以最大的放大率观测火星微粒，故此题说法为“正确”的。
单选题
Using the same technology, we have also measured the size of particles on the moon and Jupiter.
单选题
Scientists use the highest resolution microscope to watch and record the image of Martian particles on earth.
【正确答案】
B
【答案解析】[解析] 题意：科学家利用最高分辨率的显微镜在地球上观测和记录火星微粒。
根据第二段第一句“taking this image required the highest resolution microscope operated off Earth and a specially designed device to hold the Martian dust”可知观测火星微粒需要声地球外运转的显微镜和捡起火星尘埃的特殊装置，故此题说法为“错误”的。
单选题
Tom Pike said that they used to think it was no easy job to image Such small particles.
【正确答案】
A
【答案解析】[解析] 题意：Tom Pike说他们过去曾想到过观测体积如此微小的颗粒不是一件容易的事情。
根据文章第二段最后一句“we always knew it was going to be technically very challenging to image particles this small.”可知，Tom Pike他们过去一直知道，观察体积如此小的微粒具有很高的挑战性。故此题说法为“正确”的。
单选题
An electronic device has been developed to measure the weight of certain Martian particles.
单选题
After collecting the last Martian dust particle, the scientists have started to build up a portrait gallery of it.
【正确答案】
B
【答案解析】[解析] 题意：在搜集了最后的火星微粒后，科学家们已经开始为火星微粒建设一个陈列馆。
根据文章第三段倒数一、二句“and this won"t be the last dust particle…After this first success, we"re now working on building up a portrait gallery of the dust on Mars”可知这不是火星登陆器观测的最后的微粒。达成这一初步成就后，科学家们在为火星微粒建设陈列馆。故此题说法为“错误”的。
单选题
The Phoenix"s robotic arm collected the Martian dust particles for analysis on Mars.
【正确答案】
A
【答案解析】[解析] 题意：凤凰号的机械臂搜集了为分析火星用的火星微粒。
根据文章最后一段第一句“Phoenix mission is analyzing the dust and subsurface ice layers of Mars" arctic regions...”可知，凤凰号的任务是分析火星北极地区的尘埃和冰盖表面，以寻找过去火星潜在的可居性的迹象；而由本段最后一句“the particle...was part of a sample scooped by the robotic arm from the “Snow White”trench”可知微粒是机械臂从Snow White沟里挖掘到的。故此题说法为“正确”的。