NASA to launch twin probes to measure moon gravity

 　　BEIJING, Sept. 6 (Xinhuanet) -- NASA will launch on Thursday twin lunar orbiters built to map the gravity of Earth's moon in unprecedented¹ detail, media reported Tuesday.

　　The twin lunar probes, Graili-A and Graili-B, will blast off from Florida's Cape² Canaveral Air Force Station at 8:37 a.m. EDT and at 9:16 a.m. EDT respectively Thursday, according to NASA.

　　The Grail twins will travel three to four months to get to the moon under a slower but more economical plan.

　　The two spacecrafts will reach the moon around New Year's Day when they will begin to probe the moon's composition from the crust to the core, according to NASA.

　　The data collected by the probes will be used to better understand the moon's evolution and formation, NASA scientists said.

　　Researchers will also use the twin probes to pinpoint³ the best landing sites for future explorations.

　　The mission, from start to finish, costs 496 million U.S. dollars. The two Grail probes will crash into the moon after its mission.

1 unprecedented   

adj.无前例的，新奇的

参考例句：

• The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
• A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。

2 cape   

n.海角，岬；披肩，短披风

参考例句：

• I long for a trip to the Cape of Good Hope.我渴望到好望角去旅行。
• She was wearing a cape over her dress.她在外套上披着一件披肩。

3 pinpoint   

vt.准确地确定；用针标出…的精确位置

参考例句：

• It is difficult to pinpoint when water problems of the modern age began.很难准确地指出，现代用水的问题是什么时候出现的。
• I could pinpoint his precise location on a map.我能在地图上指明他的准确位置。