What is Aurora: Definition and 40 Discussions

An aurora (plural: auroras or aurorae), sometimes referred to as polar lights (aurora polaris), northern lights (aurora borealis), or southern lights (aurora australis), is a natural light display in the Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic).
Auroras are the result of disturbances in the magnetosphere caused by solar wind. These disturbances alter the trajectories of charged particles in the magnetospheric plasma. These particles, mainly electrons and protons, precipitate into the upper atmosphere (thermosphere/exosphere). The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles.
Most of the planets in the Solar System, some natural satellites, brown dwarfs, and even comets also host auroras.

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  1. S

    B What's a good website for aurora forecasts?

    I understand that we are at a peak of aurora activity, so I'd like to see a forecast like one would see at a weather website, and for the entire globe.
  2. dykuma

    A mathematical description of the physics behind Aurora?

    Maybe a bit of an odd question (not really sure where it would belong on this site to be honest), but I was wondering if anyone can explain, or at least knows of a source that explains in a quantitative way, the physics behind aurora? Now I've seen websites like this that discuss conceptually...
  3. A

    B Why are aurora always in the vicinity of Earth's poles?

    Why aurora happen near north or south pole more easily? I mean why charged particles can escape the Van Allen belts more easily to have collisions with particles in the atmosphere? Why are they harder to escape near equator? Isn't it supposed to have weaker magnetic field near the equator?
  4. davenn

    Stargazing Aurora Alert for 6th and 7th Sept

    A Geomagnetic Storm alert has been released following a CME ( Coronal Mass Ejection) caused by one or more of the flares over the last 24 hours As with last time, those of you living in higher latitudes 45 deg North or South. Canada, nthrn USA, Alaska, nthrn Europe, Iceland, southern New Zealand...
  5. davenn

    Stargazing For those aurora chasers -- a heads up

    A large coronal hole is about to become geo-effective. Another 24 hrs and it will be face on to earth. 3-4 days from now Auroral activity can be expected in high latitude locations of the northern and southern hemispheres Nthrn Europe, Canada, nthrn USA. Southern Australia ( mainly Tasmania) and...
  6. jtbell

    Stargazing Anyone looking for the aurora tonight (July 16/17)?

    Might be visible in places like New England, (upstate) New York, Michigan, Wisconsin, Minnesota, Washington state... http://www.cnn.com/2017/07/16/us/possible-northern-lights-show/ I'm way too far south, unfortunately.
  7. Solomei

    Why do Aurora colors in a bottle resemble Aurora Australis?

    I would say that this looks more like Aurora Australis. What is the reason for these changing colors? https://www.space.com/22594-aurora-bottle-northern-lights-show.html
  8. jim mcnamara

    Steve - an aurora related phenomenon

    When people find something they have never seen and do not understand they give it a name. It makes them feel like they know something, even when there really is little understanding. So somebody somewhere suggested a name for something several people reported seeing and photographing. It...
  9. R

    B Do all auroras occur in circles?

    Do the formation of auroras always occur in circles/ovals/ellipses?? What causes the shape of their formation?
  10. A

    B When to see aurora borealis in Lincoln, NE?

    Hi guys, I seem to be having problems determining if I can see the northern lights, even just a spec of if it, here in Lincoln tonight. Would someone mind helping me to catch a glimpse of it? How do I determine the time and well I guess I look in the direction of the north star as far as...
  11. thebosonbreaker

    I Aurora on Uranus? Why Are They In Large Dots?

    I have recently learned that Earth is not the only planet that has the Northern and Southern lights, as many other planets, including Jupiter and Uranus also have them. I fully understand why Earth has them and all of the science behind it, however, I also recently learned that, whereas Earth's...
  12. M

    Why can we not see auroras at lower latitudes?

    So I've been thinking about how the magnetic fields from the Earth create a magnetic mirror which accelerates the the particles in the atmosphere causing them to ionize and thus produce the auroras we see. But it is curious to me that they can only be seen in the upper most northern and southern...
  13. J

    What sparked your curiosity about the natural world and space?

    My father was an exploration geologist in Australia mainly, in his early career dad geologically mapped large areas of Australia, South Australia mostly, during the 50s and 60s, and his maps were used by the Dept of Mines. My childhood memories are filled with images of topographic maps on the...
  14. spark802

    Timelapse of Aurora Borealis

    Hi folks I shot about 260 frames on the March 17 Aurora event...iso 1600, f/4.5, Cano 550D, exp times are 12 sec for first half of movie then bumped them up to 30 secs. Imaged from a few miles north of Winnipeg, Canada.
  15. F

    Reliable Data on Polar Aurora for CERN Experiment

    Hello, I am working in an experiment proposal for a contest at CERN, and I need reliable data about the Polar Aurora. The experiment consist in using a T9 beam to produce radiation similar to the Sun's radiation and irradiate with it a capsule with gas in conditions as close as possible to...
  16. E

    Calculating what latitude aurora is visible using KP Index

    Is there a formula to calculate at what latitude you are able to see the aurora, given some value like K-index? From the NOAA website on space weather, they have some global maps with lines showing where on Earth its most likely to see the aurora, what I'm wondering is how they calculated this.
  17. rogerk8

    What Causes the Different Colors of the Aurora?

    Hi! I wonder what makes the Aurora colors. This is what I naively believe I know: Charged particles are ejected from the Sun and hits our protective magnetic field eight minutes later. At the poles, the magnetic flux density, B, is the greatest. Particles coming from the Sun are intercepted...
  18. davenn

    An Aurora Watch alert issued today

    hey guys anyone interested in seeing and or photographing aurorae an alert has been issued today 21 Aug 2013 AEST = Australian Eastern Standard Time cheers Dave
  19. davenn

    Aurora Australis: Reflections from Down Under

    nice one spark ohhhh how I so miss the Aurora ( Aurora Australis for me in the southern hemisphere) I have beem living in Sydney, Australia for the last 13 and a half years and its extremely rare for an aurora to be seen from this latitude ~ 32S From my old home in Dunedin, New...
  20. T

    Alienware Aurora 9700 Troubleshooting Help

    My father brought an Alienware Aurora 9700 after many years of service it's graphics card gave in. He replaced it with another but he applied to much thermal past which spilt off and fried the board. I don't know all the facts because he gave up on it a year ago. Today I took it out of cupboard...
  21. L

    Physics related to Aurora Borealis help?

    Hey Physics World! Not sure what sort of responses I will get here but I thought to give it a shot. I am not a total physics nerds and I don't know all that there is to know about it... but from what I have learned so far from my college courses, it is my all time favorite science! I...
  22. robphy

    Videos: time-lapse by Terje Sorgjerd (Mountain and Aurora)

    Nice time-lapse videos by Terje Sorgjerd http://vimeo.com/terjes http://vimeo.com/22439234 The Mountain http://vimeo.com/21294655 The Aurora http://www.cnn.com/video/#/video/world/2011/04/23/ctw.earth.day.photos.cnn interview
  23. KrisOhn

    Does anyone have really nice aurora where they're from. I was outside

    Does anyone have really nice aurora where they're from. I was outside of the city at an observatory last night, doing some observing, and while they're not great for maintaining your dark sky adaptation, they sure do make some great photos. The craziest part of the aurora was...
  24. G

    Temperature affect on the Aurora Borealis

    So, I'm from Northern B.C., Canada, and we would get the northern lights most nights. I know how solar winds reach Earth, and get caught up in the magnetic field, blah, blah blah. BUT, for some reason, in the wintertime on the nights when the temperature drops very low, (about -20 degrees...
  25. C

    Aurora borealis over India is it possible?

    I read on another forum that during or after the huge tsunami that hit in 2004, that supposedly aurora borealis was spotted in the skies over India. The poster said that this is an impossibility, and that is proves that the United States is the cause behind the tsunami, and that it was created...
  26. F

    Is the aurora (as in borealis ) caused by Cherenkov radiation

    Is the aurora (as in "borealis") caused by Cherenkov radiation... ...or something else? thank you. -- faye kane, idiot savant
  27. K

    Behavior of Aurora Australis Around A Dark Spot on Composite Image

    On http://en.wikipedia.org/wiki/Aurora_(astronomy ), about 1/2-way down the page, there is an image of, quote, "Aurora australis (September 11, 2005) as captured by NASA's IMAGE satellite, digitally overlaid onto the The Blue Marble composite image." Next to it, there is a rolling video of...
  28. A

    Explanation of Aurora Borealis and Aurora Australis

    1. I'm extremely confused with how they' re originated, basically explain how the aurora borealis and aurora australis are formed.
  29. S

    Why Does the Aurora Only Occur in the North Pole?

    why the aurora happens only in northern pole,why not in south pole...if it is because of the electrons of solar wind and Earth's magnetosphere then the same solar wind also got protons then why no aurora in south pole?
  30. S

    The Mystery of Aurora Borealis: Electron Acceleration

    I'm just wondering whether anyone has any theories as to what causes the electrons in the Aurora Borealis to accelerate (emitting e.m radiation)?
  31. B

    Unraveling the Mysteries of Jupiter's Auroras

    Can someone explain why it happens - on Jupiter? here's a pic http://upload.wikimedia.org/wikipedia/commons/8/8e/Jupiter.Aurora.HST.UV.jpg
  32. Ivan Seeking

    Exploring the Mysterious "Black Aurora": A UAF Research Mystery

  33. wolram

    The Aurora of 1192: Examining Medieval Europe's Climate Change

    http://eserver.org/history/aurora-of-1192.txt Since the publication of Ladourie's Histoire de climat depuis l'an mil in 1967, historians have generally accepted that the European climate deteriorated after about the year 1000. They have seen this deterioration as a cause of the Great Famine of...
  34. A

    Notes on Polar Aurora: A Guide

    hello anyone have some notes on polar aurora? thank you
  35. Ivan Seeking

    Aurora borealis with sunset, moonrise, and a clear sky

    http://www.coasttocoastam.com/gen/page626.html?theme=light http://www.coasttocoastam.com/
  36. D

    Aurora Phenomana: Door to Dimensions & City in Sky

    the aroura has many strange acourenses including hints of a dorr between dimensions and a city visible in the sky. Add any information you feel like and don't with hold any thing. :smile:
  37. Arctic Fox

    Capture an Aurora: Can We Harness the Energy?

    Could there be a way to capture the energies that create an aurora using an electromagnetic field? It seems as if the particles travel down the Earth's magnetic field like a funnel - which then ionizes the atmosphere. What if there was no atmosphere to react with? Where would the energies go...
  38. benzun_1999

    Creating an Aurora Lights Model for School Fair

    hi all, In our school there is a geography fair and i was just wondering weather it is possible to create aurura lights model. i feel using a hologram a fairly good model can be made. But i want something more better. I hope some one can help me. :confused:
  39. G

    Aurora Borealis Viewed From My Window

    I can so totally see the aurora borealis from my window. I've never seen it before. It's so cool. I think I'm going to get my guitar and go outside and play... its cold, but i always play for the full moon, figure the lights are just as special. Sooooo Cool...
  40. J

    Unlocking the Mystery of Aurora Borealis: What Causes It?

    What causes the Aurora Borealis?