We were not altogether sure that the comet would miss the Earth.

我们不太确定这颗彗星是否会错过地球。

《柯林斯英汉双解大词典》

The orbit of this comet intersects the orbit of the Earth.

这颗彗星的轨道和地球的轨道相交。

《柯林斯英汉双解大词典》

The trip from Earth by "Philae" had taken ten years! The scientists had no idea what the surface of the comet would be like.

“菲莱”号从地球出发的旅行已经花了十年的时间！科学家们不知道彗星的表面会是什么样子。

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Nanodiamonds are produced under only a very high temperature and high pressure event, such as a comet striking Earth.

VOA: special.2009.01.20

One argument against the comet theory is that a comet would have left a large hole in the Earth's surface.

VOA: special.2009.01.20

Scientists at the Goddard Space Flight Center in Greenbelt,Maryland, found the substance glycine in material brought back to Earth from a comet.

VOA: special.2009.09.30

The severity of the laboratory test was equivalent to an oblique collision with the rocky surface of the Earth - a comet coming in at an angle of less than 25 degrees from the horizon, rather than head on (perpendicular to the Earth's surface).

BBC: Comets could have seeded life on Earth

It is huge some 100km across and seems to be the largest of between three and five craters that formed within a few hours of each other as the lumps of a disintegrated comet hit the earth one by one.

ECONOMIST: The rise of the dinosaurs

One answer might be that the two impacts were, in effect, simultaneous that the objects which created Shiva and Chicxulub were the daughters of a comet that had broken up in space and hit the Earth a few hours apart, as the pieces of comet Shoemaker-Levy 9 hit Jupiter in 1994.

ECONOMIST: Mass extinctions