This is one of the hallmarks of impact craters.

陨石坑都有这样的特点。

The young Earth was once completely covered by impact craters.

年轻的地球曾经完全被陨石坑覆盖。

You cannot take a step on Mercury without encountering an impact crater.

遍布水星，你找不到一块没有撞击坑的地方。

And many of the shadowy shapes Galileo saw we later realized were impact craters.

伽利略看到的许多模糊的形状我们后来意识到是陨石坑。

Major thing that we'll wind up getting is a very nice fresh impact crater.

我们最终会获得一个非常理想的新产生的撞击坑。

An impact crater is formed when a space object crashes into a planet or moon.

撞击坑是太空物体撞上行星或月球时形成的。

It includes over 12,000 impact craters, 81 impact basins, 17 rock types and 14 types of structures.

包括 12，000 多个撞击坑，81 个撞击盆地，17 种岩石类型和 14 种结构。

Researchers looked at impact craters on Earth and its moon that were larger than 20 kilometers wide.

研究人员观察了地球和月球上直径超过20公里的陨石坑。

It was yellow and orange and red and black, and didn't seem to have any obvious impact craters.

黄、橙、红和黑色交织，同时也没有任何明显的陨石坑。

Together they gathered a list of the large marks that asteroids leave on planets and other objects, also known as impact craters.

他们一起收集了小行星在行星和其他物体上留下的巨大痕迹，也被称为撞击坑。

It was, indeed, an impact crater.

它确实是一个撞击坑。

And in those areas they actually found a fairly circular feature, and in that, they deduced that that might be an impact crater.

他们在那些区域发现了相当圆的地形，就这样他们推测那可能是个撞击坑。

It has mountains and plains, rivers, lakes and seas, sand dunes and some impact craters.

它有高山平原，有河流、湖泊和海洋，有沙丘和一些陨石坑。

Still, the surface appears to be very young: about a thousand impact craters have been found, and they're evenly distributed around the planet.

人们已经发现了大约1000个陨石坑，它们均匀地分布在这个星球上。

In 950,000 years the meteor crater in Arizona, which is considered the best preserved meteorite impact crater on Earth will have completely eroded away.

美国亚利桑那州的陨石坑被认为是地球上保存最完好的陨石撞击坑，在 95 万年的时间里，它将完全被侵蚀掉。

So scientists were shocked when they discovered another large impact crater, buried a kilometer under Greenland's Hiawatha glacier.

因此，当科学家们发现另一个巨大的陨石坑时，他们感到震惊，这个陨石坑埋在格陵兰岛的 Hiawatha 冰川下一公里处。

There are more than 43,000 documented impact craters on Mars, so why are scientists so interested in this one?

火星上有超过 43,000 个记录在案的陨石坑，那么为什么科学家对这个陨石坑如此感兴趣呢？

And it may have been active fairly recently, as evidenced by the  lack of impact craters in the surrounding area.

它可能最近很活跃，周围地区没有撞击坑就证明了这一点。

With Magellan images we see really small number impact craters and such a small numbers about a thousand, because we know the radar which impact craters can actually date to surface too.

我们看到麦哲伦图像真的很小数量的陨石坑, 因为我们知道雷达表面的陨石坑实际上已经追溯到表面。

The most prominent feature, is a feature called the " Caloris Basin" , which is a very large impact crater that is about maybe 900 miles in diameter.

这个特征最显著的陨石坑被称作卡洛里斯盆地这个坑如此大直径可能有900英里。