美科學家稱月球正在縮小

The Man in the Moon has become the latest victim of contraction in the housing market.

Astronomers reporting on Thursday in the US journal Science said they had found previous undetected landforms which indicate that Earth's satellite has been shrinking... albeit by only a tiny amount.

The intriguing features, called lobate scarps, are faults created when the Moon's once-molten interior began to cool, causing the Lunar surface to contract and then crinkle, they said.

Relative to the Moon's age, estimated at around 4.5 billion years, the contraction is recent, occurring less than a billion years ago, and is measured at about 100 meters (325 feet).

Lobate scarps were first spotted near the lunar equator in the 1970s by panoramic cameras aboard the Apollo 15, 16 and 17 missions.

Fourteen new faults have been been spotted in high-resolution images taken by NASA's Lunar Reconnaissance Orbiter.

The new discoveries show that the scarps are globally distributed and not clustered in equatorial regions, and this provides powerful evidence for the contraction scenario.

The investigation was headed by Thomas Watters of the Center for Earth and Planetary Studies at the Smithsonian Museum's National Air and Space Museum, Washington.

“月球人”成爲月球“房地產市場”緊縮的最新受害者。

天文學家於上週四在美國《科學》雜誌發表的報告中稱，他們發現了月球上出現了一些之前未被勘測到的地貌，這些地貌表明地球的這顆衛星正在縮小——儘管幅度很小。

這些被稱爲“葉狀陡坡”的有趣的地貌特徵是在月球一度熔化的內核開始冷卻的過程中形成的斷層，這一過程使得月球表面發生收縮，並出現褶皺。

這一收縮過程是在“近期”發生的，相對於月球45億年的高齡，這個“近期”指的是不到10億年前。但據測算這一收縮的幅度僅爲約100米（325英尺）。

“葉狀陡坡”於上世紀70年代在月球赤道附近首次被發現，是阿波羅15號、16號、17號飛船上的全景照相機拍到的。

之後又有14處新的斷層被發現，美國宇航局的月球勘測軌道飛行器拍攝了這些斷層的高清照片。

這些新發現表明，葉狀陡坡分佈在月球各地，並非只是集中在月球的赤道地區，這也爲月球正在縮小這一假設提供了有力證據。

這項研究由華盛頓史密森國家航空航天博物館地球與行星研究中心的托馬斯沃特斯負責開展。

Vocabulary:

fault: a break in the continuity of a body of rock or of a vein, with dislocation along the plane of the fracture（斷層）

panoramic: bird's-eye, as from an altitude or distance（全景的）

high-resolution: having or capable of producing an image characterized by fine detail（高分辨率的）