《明史·志·卷四》
宣德元年二月戊子日，北方黑色氛气朝东西向横豆于天空。
宣德元年二月戊子，北方黑气东西亘天。
On the day of Wuxu in February of the first year of Xuanade, black qi from the North crossed the sky from east to west.
<s>[INST] Kindly elucidate the central themes in this passage in English: 宣德元年二月戊子，北方黑气东西亘天。 [/INST] On the day of Wuxu in February of the first year of Xuanade, black qi from the North crossed the sky from east to west.</s>
Kindly elucidate the central themes in this passage in English: 宣德元年二月戊子，北方黑气东西亘天。
user
On the day of Wuxu in February of the first year of Xuanade, black qi from the North crossed the sky from east to west.
assistant