火星有四季？

蓝利霞

New observations of mud cracks made by the Curiosity rover show that high-frequency， wet-dry cycling occurred in early Martian surface environments， indicating that the red planet may have once seen seasonal weather patterns or even flash floods.

“These exciting observations of mature mud cracks are allowing us to fill in some of the missing history of water on Mars. How did Mars go from a warm， wet planet to the cold， dry place we know today？ These mud cracks show us that transitional time， when liquid water was less abundant but still active on the Martian surface，” said Nina Lanza， the lead investigator of the ChemCam instrument onboard the Curiosity rover.

After years of exploring land， the rover entered a new area filled with sulfates（硫酸鹽）， marking a major environment transition. In this new environment， the research team found a change in mud crack patterns， signifying a change in the way the surface would have dried. This indicates that water was still present on the surface of Mars occasionally， meaning water could have been present for a time， evaporated， and repeated until mud cracks formed. Additionally， the rover found evidence that the mud cracks were only a few centimeters deep， which could mean that wet-dry cycles were seasonal， or may have even occurred more quickly， such as in a flash flood.

These findings could mean that Mars once had an Earth-like wet climate， with seasonal or short-term flooding， and that Mars may have been able to support life at some point. “Whats important about this phenomenon is that its the perfect place for the formation of polymeric molecules required for life， including proteins， if the right organic molecules were present at this location，” another researcher said， “Wet periods bring molecules together while dry periods drive reactions to form polymers（聚合物）. When these processes occur repeatedly at the same location， the chance increases that more complex molecules formed there.”

（材料出自Science Daily网站，有删改）

1. What can we know from Nina Lanzas words？

A. Mars had been a warm， wet planet.

B. The Martian surface has abundant liquid water.

C. Nina can show lead investigators the transitional time.

D. Nina has filled in the missing history of water on Mars.

2. What is the main idea of the third paragraph？

A. The formation of the rover.

B. The new finding of the researchers.

C. The exploration of the rover.

D. The new transition of the researchers.

3. What may be the consequence of Earth-like wet climate in Mar？

A. Flash flood. B. Proteins variety.

C. Life formation. D. Molecules complexity.

4. In which section of a website may this text appear？

A. Health.B. Science.

C. Education. D. Entertainment.

1. A。解析：细节理解题。根据材料第二段中的“How did Mars go from a warm， wet planet to the cold， dry place we know today？”，我们可知，之前的火星是一个温暖而潮湿的星球。故选A。

2. B。解析：主旨大意题。根据材料第三段中的“the research team found a change in mud crack patterns”和“Additionally， the rover found evidence that the mud cracks were only a few centimeters deep”，我們可知，第三段主要讲了研究团队的新发现。故选B。

3. C。解析：推理判断题。根据材料最后一段的第一句“These findings could mean that Mars once had an Earth-like wet climate， with seasonal or short-term flooding， and that Mars may have been able to support life at some point.”，我们可知，如果火星有像地球一样的潮湿的气候和季节变化等，那么火星在某个时刻或许能支持生命存在。故选C。

4. B。解析：推理判断题。通读整篇材料，我们可知，材料介绍的是科学家通过观察火星泥浆裂缝，发现火星之前可能有类似地球的四季模式甚至是暴洪。这属于科学研究的范畴，因而这篇文章最有可能出现在网站的“科学”版块。故选B。