字幕表 動画を再生する 英語字幕をプリント We finally figured out what’s been making a huge greek letters by the north and south poles. My money’s on frat guys. Hey there my shining beacons, Julian here for DNews. I’m sure you’ve all heard of the Aurora Borealis, or if you’re a viewer south of the equator, the Aurora Australis. They’re dazzling natural light shows that happen when charged particles like electrons and protons from the solar wind excite oxygen and nitrogen in our upper atmosphere. Normally the Aurorae can occur 65-70 degrees north or south of the equator but they can happen at higher latitudes. Occasionally these take the shape of the greek letter theta and we had no idea why. You see, the earth is surrounded by a magnetic field thanks to its spinning iron core. These magnetic field lines loop between the north and south pole and form the magnetosphere. The magnetosphere deflects the charged particles of the solar wind, and it’s the reason we have an atmosphere while poor little Mars has had its almost totally stripped away. But the field lines don’t all connect, and plasma rides the broken ones down to the ionosphere, getting faster and more dense. When it meets our air energizes the gases, which then radiate that energy away as light. Normally the plasma that moves to the higher latitudes cools but sometimes it gets more energetic and makes these theta auroras. Combining data from the European Space Agency’s Cluster satellites and NASA’s IMAGE satellites, the mystery of why this cold plasma heats up and forms this shape has been solved. As it turns out this plasma gets trapped when broken field lines close, and it causes them to become relatively hot again. See what you can do when you work together? It’s another nifty trick of nature and I don’t care how good your fireworks are on new years, nothing beats charged particles from 150 million kilometers away traveling down a magnetic funnel to make green and red ribbon light shows in the sky. If you’re a crazy person like Trace then you want to shoot rockets at everything. He explains why the Aurora should be one of those things over here. Is there another natural occurrence that boggles your mind? Do you want us to look into some other mystery of nature? Let us know in the comments and I’ll see you next time on DNews.
B2 中上級 空に浮かぶ不思議な光を解説! (Mysterious Lights In The Sky Explained!) 102 13 Cheng-Hong Liu に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語