首页
登录
职称英语
Northern lights is the name of a light phenomenon often seen in the northern
Northern lights is the name of a light phenomenon often seen in the northern
游客
2023-10-31
21
管理
问题
Northern lights is the name of a light phenomenon often seen in the northern regions. The lights have been around since Earth formed an atmosphere—the dinosaurs saw it, early humans saw it and our descendants will see it. The scientific name for the phenomenon is "Aurora Borealis", aurora for short.
An aurora is a sporadic, generally faint, atmospheric phenomenon usually seen in the night sky from locations at high latitudes. More commonly known as the "northern lights," it may first appear as a faint, milky glow low in the north, too dim for the human eye to detect any color but bright enough to silhouette clouds near the horizon. It may develop into steady greenish arcs or form glaring, swirling curtains of yellow-green light. During the most dramatic displays visible from regions at middle latitudes, such as central Europe and the United States, a crimson glow fills much of the sky. It was this form that inspired European scientists of the 1600s to call the phenomenon aurora borealis, literally "northern dawn," but it also occurs at high southern latitudes, where it is formally called aurora australis, "southern dawn." The same processes are at work in both hemispheres—not just on Earth, but on other planets as well—and today, scientists simply refer to this phenomenon as an aurora. The ghostly forms of an aurora include quiescent patches, veils, and arcs, and rapidly moving rays and curtains.
Many historical accounts of the northern lights from areas far south of its usual location exist. An early Chinese record describes it as a "red cloud spreading all over the sky." The Roman philosopher Seneca wrote that an aurora in A.D. 37 tricked the emperor into sending troops to aid what he thought was the burning seaport of Ostia, "when the glowing of the sky lasted through a great part of the night, shining dimly like a vast and smoking fire." In 1583, similar "fires in the air" mobilized thousands of French pilgrims, who prayed to avert the wrath of God. On September 15, 1839, an intense aurora dispatched firefighters throughout London.
What causes the showers of charged particles that create the northern lights? Ultimately, the source lies in the solar wind, a fast-moving stream of particles constantly flowing from the Sun that carries the Sun’s magnetic field out into space. The solar wind, typically moving at 250 miles(400 kilometers)per second, flows past Earth’s magnetic field and molds it into an elongated bubble or cavity, compressing its sunward side and stretching its night side far beyond the Moon’s orbit. Under certain conditions, the solar wind’s magnetic field can merge with Earth’s, creating electrical currents that drive protons and electrons into the polar atmosphere. Powerful events occurring on the Sun can drive enormous changes in the solar wind, increasing both its speed and density and enhancing its effect on Earth. [br] According to the passage, an aurora can be an atmospheric phenomenon EXCEPT that is seen ______.
选项
A、in the night sky at high southern latitudes
B、in the night sky at high northern latitudes
C、on top of high mountains on the Earth
D、at the southern regions of other plants
答案
C
解析
第2段介绍了极光的颜色和可看到极光的地方,浏览该段之后就可以发现C中的high mountains在原文并无提及,因此C为答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3145109.html
相关试题推荐
Alltheflights______becauseofthesnowstorm,wehadtotakethetraininstea
Aphenomenonemergesthatanincreasingnumberofon-jobpeople,especially
Thepoliceaskedthechildren______crossthestreet______thetrafficlightstur
Wheredidtheattackhappenyesterday?[originaltext]RebelsinnorthernUgan
WhydidNorthernEuropeanpeoplecometosettledownintheUnitedStates?[br]
ThemanwantstogetthefollowingdetailsoftheflightsEXCEPT[br][original
The______ofaculturalphenomenonisusuallyalogicalconsequenceofsomephysi
Northernlightsisthenameofalightphenomenonoftenseeninthenorthern
A.incidentB.whenC.includeD.flightsE.informedF.carriagesG.ca
A.incidentB.whenC.includeD.flightsE.informedF.carriagesG.ca
随机试题
Itisreportedthatacoupleregisteredformarriagesincetheyhavechatted
[originaltext] (5)Francehasbecomethefirstcountrytobansupermarketsfro
查找汉语成语,一般可利用的工具书有( )。A.《辞源》 B.《辞海》 C.
下列吊顶材料价格最低的是()。A.铝合金平板 B.纸面石膏板 C.铝合金
某地下空间与城市交通隧道一体化建没,交通隧道总长度1500m,可双向通行非危险品
为满足施工要求,水泥的初凝时间不宜太(),终凝时间不宜太()。A.长,短
关于SARS症状叙述错误的是A.严重者可于发病6~12天后出现呼吸加速、气促,甚
小儿发生惊厥时首先采取的护理措施是()。A.送入抢救室 B.解松衣物,平卧,
典型的()是单位的人事关系系统。A.人工智能和专家系统 B.事务处理系统
某机房正在进行室内装修,进入动火作业阶段发生火灾,值班人员立即按下气体灭火控制器
最新回复
(
0
)