13 Noctilucent clouds seemed to first appear after the 1883 eruption of krakatoa and are now a common sight .
13夜光云似乎首次出现是在1883年喀拉喀托火山（krakatoa）喷发之后，而现在则已司空见惯。
12 Highest of them all : 50 miles up , noctilucent , or " night shining , " clouds glow an eerie bluish white .
12最高的云：夜光云，也称“黑夜闪耀”云，存在于在离地50英里的高空，云朵焕发怪异的蓝白色光芒。
Ethereal : noctilucent clouds are crystals of ice hanging around 80km high in the atmosphere that catch the light of the sun long after it has set on the horizon .
飘渺：夜光云是悬挂在大气80千米上空，在太阳升上地平线后吸收太阳光的晶体冰。
Noctilucent clouds are crystals of ice hanging around 50 miles high in the atmosphere that catch the light of the sun long after it has set on the horizon .
夜光云：太阳从地平线升起很长时间后，存在于大气层中50米左右高度的冰晶吸收阳光而形成。
We became aware of noctilucent clouds here at wired science in july when the strange glowing clouds began appearing over the united states and europe , much farther south than they were normally seen .
