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New NASA videos reveal how Earth’s moon evolved

来源:FoxNews.com 作者: 时间:2012-03-16 Tag: 点击:

 

Two new NASA videos use the latest close-up imagery of the moon from the Lunar Reconnaissance Orbiter(月球侦察轨道器) to reveal Earth's natural satellite in a whole new light.

One video zooms over the moon to reveal its most prominent features. Imagery from the spacecraft shows these lunar highlights in high-resolution detail, revealing deep craters(环形山), towering(高耸的) mountains, and even leftover equipment at the NASA's Apollo moon landing sites.

This narrated "best-of" tour of the moon includes photos of Orientale Basin, Shackleton crater, South Pole-Aitken Basin, Tycho crater, Aristarchus Plateau, Mare Serenitatis, Compton-Belkovich volcano, Jackson crater and Tsiolkovsky crater.

The second video uses Lunar Reconnaissance Orbiter photos to animate the history of the moon from its formation around 4.5 billion years ago through today.

Both videos were created by the Lunar Reconnaissance Orbiter team at NASA's Goddard Space Flight Center in Greenbelt Md., in honor of the probe's(太空探测器) 1,000th day in orbit. LRO was launched June 18, 2009, from Cape Canaveral, Fla.

The moon is thought to have been created when a large space rock slammed into Earth and broke off a chunk of our planet. This collision was so powerful it would have melted rock, leaving the moon a hot, liquid blob(一柔软、无定形的块状物) for its early years. As this molten magma(岩浆) melted over time, the lunar crust formed.

But the moon was soon disturbed again by another huge asteroid(小行星) impact. Between 4.5 and 4.3 billion years ago, scientists think a giant object crashed into the moon's south pole and created the South Pole-Aitken Basin. This feature, still visible today, is one of the two largest known impact basins in the solar system.

And that collision was not an isolated incident. The moon went through an early period of bombardment(撞击, 碰撞) by many space rocks of varying sizes, though none were quite as gigantic(巨大的) as the rock responsible for the South Pole-Aitken Basin.

The video illustrates the effect of this action on the early moon. Because the moon's insides hadn't completely cooled by this point, magma would have seeped(渗出) through the cracks on the moon's surface caused by these impacts.

Over time, this volcanic activity subsided(平息, 减退) as the moon further cooled and impacts became less frequent. The moon's current barren(荒地), seemingly unchanging face belies(掩饰) the volatility(挥发性) of its early life, though.


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