时间:2010-09-11 12:57:52
Laboratory tests aboard NASA''s Phoenix Mars Lander have identified water in a soil sample. The lander''s robotic arm delivered the sample Wednesday to an instrument that identifies vapors produced by the heating of samples.
"We have water," said William Boynton of the
The robotic arm is a critical part of the Phoenix Mars mission. It is needed to trench into the icy layers of northern polar Mars and deliver samples to instruments that will analyze what Mars is made of, what its water is like, and whether it is or has ever been a possible habitat for life.
The soil sample came from a trench approximately 2 inches deep. When the robotic arm first reached that depth, it hit a hard layer of frozen soil. Two attempts to deliver samples of icy soil on days when fresh material was exposed were foiled when the samples became stuck inside the scoop. Most of the material in Wednesday''s sample had been exposed to the air for two days, letting some of the water in the sample vaporize away and making the soil easier to handle.
"Mars is giving us some surprises," said
Since landing on May 25,
The mission is examining the sky as well as the ground. A Canadian instrument is using a laser beam to study dust and clouds overhead.
"It''s a 30-watt light bulb giving us a laser show on Mars," said Victoria Hipkin of the Canadian Space Agency.
A full-circle, color panorama of
"The details and patterns we see in the ground show an ice-dominated terrain as far as the eye can see," said Mark Lemmon of Texas A & M University, lead scientist for Phoenix''s Surface Stereo Imager camera. "They help us plan measurements we''re making within reach of the robotic arm and interpret those measurements on a wider scale."
参考答案: C 答案解析: Water in a soil sample.
1What was discovered by NASA''s Phoenix Mars Lander on Mars?
A.Vast lakes.
B.Flowing rivers.
C.Water in a soil sample.
D.Living things.
参考答案: C 答案解析: The samples got stuck inside the scoop.
2Why did the first two attempts to deliver samples fail?
A.The sample vaporized away.
B.Fresh material was exposed to the air.
C.The samples got stuck inside the scoop.
D.The robotic arm hit a hard rock.
参考答案: A 答案解析: Scientists have been trying to break the ice-rich layers of soil on Mars.
3Which one of the following statements is NOT meant by the writer?
A.Scientists have been trying to br