1.
Or are they being formed as a result of meteoroids or sunlight hitting the surface?
或者，它们是因为陨石撞击或阳光照射表面而产生的结果？
2.
The instantaneous release from an impact would potentially kill off species in a few thousand years.
陨石撞击是瞬间事件，理论上几千年内就能杀死大量物种。
3.
In this sense, the Chicxulub crater is the crucible of human evolution.
从这个角度来说，奇虚乐陨石撞击事件可说是人类演化的推手。
4.
Geochemical Features of the Meteorite Impact Around Eocene/ Oligocene Boundary Layer in Central Eastern Pacific Region
东太平洋中部始新世/渐新世界线陨石撞击的地球化学证据
5.
When planets are bombarded by asteroids or comets,
当星球被陨石或彗星连续撞击时，
6.
Massive meteorite strikes continued for hundreds of millions of years, some blasting craters more than1,000 kilometers in diameter.
巨大陨石的撞击持续了几亿年，有些撞击所产生的陨石坑，直径超过1000公里。
7.
Small meteorites have left impact craters all over the planet’s surface.
这个行星的表面布满了小块陨石留下的撞击坑。
8.
Meteoroids or other space rocks smashed into the newly-forming planets and moons.
陨石或者其它太空岩石猛裂撞击形成不久的行星和卫星。
9.
Mercury is covered in craters - hollows made by huge space rocks crashing into it.
水星的表面有许多陨石坑，这些坑是由巨大的太空岩石撞击而成的。
10.
Successive impacts would create a large number of metamorphosed regions in the vicinity of craters.
连续的撞击会在陨石坑附近，造成很多变质的区域。
11.
Large meteor impacts may have occasionally thickened and warmed the atmosphere.
大型陨石的撞击则可能偶发的使大气密度及温度增加。
12.
Do you know that you are four times more likely to die from an asteroid hitting the Earth than being struck by lightning?
您知道您因陨石撞地球而死亡的机率比被闪电击毙高出四倍吗？
13.
The age of each flow can then be determined by measuring its density of impact craters.
岩浆流的个别年龄可以藉测量其撞击陨石坑的密度而决定。
14.
Studies of meteorites are now providing evidence for the collisional-heating hypothesis.
目前对于陨石的研究，提供了证据支持撞击加热假说。
15.
Geologists agree that the Sudbury impactor was at least eight kilometers( about five miles) across.
地质学家同意，造成陨石坑的外太空撞击物，直径至少八公里。
16.
They estimated it would leave a crater hole in the surface between one and two kilometers across.
他们估计，这一撞击在月球表面留下了直径为一到两公里的陨石坑。
17.
It is about7000 million years old measured by isotope geological method.
假如该坑与上述三个陨石坑是同一系列的外来天体撞击地球事件。
18.
A scar on the earth's surface left from the impact of a meteorite.
陨星坑陨石对地表冲击所造成的痕迹