aurora borealis: คุณกำลังดูกระทู้
Question What are the northern lights?
The northern lights, one of several astronomical phenomena called polar lights (aurora polaris), are shafts or curtains of colored light visible on occasion in the night sky.
Polar lights (aurora polaris) are a natural phenomenon found in both the northern and southern hemispheres that can be truly awe inspiring. Northern lights are also called by their scientific name, aurora borealis, and southern lights are called aurora australis.
Sten Odenwald, author of The 23rd Cycle: learning to live with a stormy star (New York, Columbia University Press, c2001), provides insight into how northern lights are generated:
The origin of the aurora begins on the surface of the sun when solar activity ejects a cloud of gas. Scientists call this a coronal mass ejection (CME). If one of these reaches earth, taking about 2 to 3 days, it collides with the Earth’s magnetic field. This field is invisible, and if you could see its shape, it would make Earth look like a comet with a long magnetic ‘tail’ stretching a million miles behind Earth in the opposite direction of the sun.
When a coronal mass ejection collides with the magnetic field, it causes complex changes to happen to the magnetic tail region. These changes generate currents of charged particles, which then flow along lines of magnetic force into the Polar Regions. These particles are boosted in energy in Earth’s upper atmosphere, and when they collide with oxygen and nitrogen atoms, they produce dazzling auroral light.
Odenwald further tells us “Aurora are beautiful, but the invisible flows of particles and magnetism that go on at the same time can damage our electrical power grid and satellites operating in space. This is why scientists are so keen to understand the physics of aurora and solar storms, so we can predict when our technologies may be affected.”
Can I see them anywhere?
Yes, although they are more frequent at higher latitudes and places like Alaska, Canada, and Antarctica, closer to the Earth’s poles. Occasionally, they have been seen closer to the equator, and even as far south as Mexico. To view them, look in the direction of the closest pole (the northern horizon in the northern hemisphere, the southern horizon in the southern hemisphere).
Can I see them at any time of the year?
Yes. In some areas, such as Alaska or Greenland, they may be visible most nights of the year. And they occur at any time of the day, but we can’t see them with the naked eye unless it’s dark.
What causes the colors and patterns?
Colors and patterns are from the types of ions or atoms being energized as they collide with the atmosphere and are affected by lines of magnetic force. Displays may take many forms, including rippling curtains, pulsating globs, traveling pulses, or steady glows. Altitude affects the colors. Blue violet/reds occur below 60 miles (100 km), with bright green strongest between 60-150 miles (100-240 km). Above 150 miles (240 km) ruby reds appear.
Fun Facts about northern lights
- According to Neil Bone (The Aurora: sun-earth interactions, 1996), the term aurora borealis–northern dawn–is jointly credited to have first been used by Pierre Gassendi (1592-1655) and Galileo Galilei (1564-1642), who both witnessed a light display on Sept. 12, 1621. However, Bone also includes a description of the northern lights made 1,000 years prior by Gregory of Tours (538-594.) It included the phrase, “… so bright that you might have thought that day was about to dawn.”
- Auroras have been observed since ancient times.
- The height of the displays can occur up to 1000 km (620 miles), although most are between 80-120 km.
- Auroras tend to be more frequent and spectacular during high solar sunspot activity, which cycles over approximately eleven years.
- Some displays are particularly spectacular and widespread and have been highlighted in news accounts. Examples include auroral storms of August-September, 1859, Feb 11, 1958, (lights 1250 miles wide circled the Arctic from Oregon to New Hampshire) and March 13, 1989, (the whole sky turned a vivid red and the aurora was seen in Europe and North America as far south as Cuba).
- Legends abound in northern cultures to explain the northern lights. Some North American Inuit call the aurora aqsarniit (“football players”) and say the spirits of the dead are playing football with the head of a walrus. Often legends warn children that the lights might come down and snatch them away.
- June 1896, Norwegian Kristian Birkeland, the “father of modern auroral science,” suggested the theory that electrons from sunspots triggered auroras.
- Yellowknife (Northwest Territories, Canada) is the capital for aurora tourism.
- The earliest known account of northern lights appears to be from a Babylonian clay tablet from observations made by the official astronomers of King Nebuchadnezzar II, 568/567 BC.
- Some people claim to hear noises associated with the northern lights, but documenting this phenomenon has been difficult.
Published: 11/19/2019. Author: Science Reference Section, Library of Congress
The Aurora Borealis
This video explains how particles originating from deep inside the core of the sun creates northern lights, also called aurora borealis, on our planet.
See an extended multimedia version of this video at forskning.no (only in Norwegian):
This video is produced by forskning.no in collaboration with the Department of Physics at the University of Oslo.
Production, animation and music: Per Byhring
Script: Arnfinn Christensen
Scientific advisors: Jøran Moen, Hanne Sigrun Byhring and Pål Brekke
Video of the northern lights: arcticlightphoto.no
Video of coronal mass ejection: NASA
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All About Auroras: Aurora Borealis (Northern Lights) and Aurora Australis for Kids – FreeSchool
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Auroras (aurora borealis in the northern hemisphere, and aurora australis in the southern hemisphere) are beautiful, mysterious light displays in the sky that are caused by solar wind from the sun interacting with the earth’s magnetosphere. Many different myths and legends have been associated with the aurora over the years. Come and learn about them in this fun and educational video!
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NASA UHD Video: Stunning Aurora Borealis from Space in Ultra-High Definition (4K)
Earth From Space Live Video: https://www.youtube.com/watch?v=86YLFOog4GM
Using timelapses shot from the International Space Station, showing both the Aurora Borealis and Aurora Australis phenomena that occur when electrically charged electrons and protons in the Earth’s magnetic field collide with neutral atoms in the upper atmosphere
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Daily Challenge #66 /Bob Ross Style / Northern Lights Painting / Aurora Borealis Painting
Daily Challenge 66 /Bob Ross Style / Northern Lights Painting
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Eye of the Storm 4K Ultra HD
Update: Join me on a timelapse and aerial expedition in Iceland! EvosiaStudios.com/workshops/
Eye of the Storm is a winter saga in Iceland. In Iceland there are many kinds of storms. Ice, snow, rain, sand, ash, solar, magnetic, and more.
Storms are agents of change. While often destructive and unpredictable, they also demonstrate the unyielding power of nature. They reveal nature’s beauty and its hand in creating the landscapes we see today.
Shot in Iceland between February and March, 2014, I was lucky enough to witness and film the power of an Xclass solar flare and coronal mass ejection hitting our atmosphere. The resulting auroras were a sight hard to believe, even in person and seeing it with my very own eyes. Enjoy the film!
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Music: The Eye of the Storm by Shaun Diaz, http://www.shaundiazmusic.com
Special thanks to our sponsors for making this film possible:
Kessler Crane Film equipment, motion control gear http://kesslercrane.com
Glacier Rental Car Iceland car rentals http://glaciercarrental.is
I also want to give thanks and appreciation to Thorvardur Arnason for his friendship and invaluable help during my trip in Iceland. He is an amazing photographer as well as a timelapse filmmaker. http://thorri.is
Shot on the Canon 1DC and 5D Mk III in 5K raw. Motion control using Kessler Crane Cinedrive, Shuttlepod Mini, Turntable and Oracle. Edited and available in Cinema 4K and Ultra HD.
นอกจากการดูบทความนี้แล้ว คุณยังสามารถดูข้อมูลที่เป็นประโยชน์อื่นๆ อีกมากมายที่เราให้ไว้ที่นี่: ดูวิธีอื่นๆMusic of Turkey
ขอบคุณที่รับชมกระทู้ครับ aurora borealis