It refers to Niflheim which is a far northern region of icy fogs a Norse mythology.

它描述的是一个遥远的北方地区的冰雾北欧神话中的死人国。

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Most comets that fly into the inner solar system seem to come from the outer region of the Oort cloud - a region of icy dust and debris left over from the birth of the solar system.

大部分飞入内太阳系的彗星似乎都来自奥特云的外部区域——奥特云是自太阳系诞生以来剩余的冰尘与残骸形成的区域。

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The cloud of dust comes from the Kuiper belt, the region beyond Neptune that contains small, icy bodies, including Pluto.

这些尘埃云来自柯伊伯带(Kuiper belt)，柯伊伯带是海王星之外的一片区域，充满了小型的冰封物体，冥王星就包括在柯伊伯带中。

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Some schools in north-east England will be closed again on Tuesday as the Met Office forecasts more icy conditions for the region.

BBC: North East schools closed again due to snow

"First, this icy 'super-Earth' dominates the region around its star that in our Solar System is populated by the gas-giant planets, Jupiter and Saturn, " he said.

BBC: NEWS | Science/Nature | Planet hunters find 'super-Earth'

The U.S. Environmental Protection Agency has singled out the greater Salt Lake region as having the nation's worst air for much of January, when an icy fog smothers mountain valleys for days or weeks at a time and traps lung-busting soot.

NPR: Sickening Fog Settles Over Salt Lake City Area