Our local forecaster (the best0 Dick Goddard, said we may be able to see the northern lights for a few nights.
never having seen them before, i must ask
What do they look like?
My son wants to know what exactly causes them?
Thank you.
This site should answer both your question and nilla wafer’s:
No insult was intended in my making up a name for your son. I’m in a strange mood.
why thanks.
No, thats cute !
nilla wafer.
I think he was once registered as mango.
To keep track of when auroras are due (and other interesting astronomical phenomena like meteor showers, comets, planet conjunctions), pop into www.spaceweather.com every now and then.
To keep track of when auroras are likely (and other interesting astronomical phenomena like meteor showers, comets, planet conjunctions), pop into www.spaceweather.com every now and then.
Also check the Kp index (bar graph on the “satellite environment plot” pane at the bottom of the page) at http://www.sec.noaa.gov/today2.html . The Kp index has to go to at least 7 for me to see the aurora here in Chicago.
There is also a lot of info at www.spacew.com. Click on “auroral activity” at the top, then on “ground based sighting reports” on the left. There are no recent ones for North America I believe because the Kp index peaked yesterday during daylight hours.
And while you’re on that page, click on the link “Participate in our Discussion Forum” and read the comments.
I only saw the Northern Lights once. First, they looked like a great cloud of glowing bright red gas (none of us had seen them before so we thought there may have been a major industrial accident in Louisville). Then great balls of white light appeared in the sky and projected greenish streamers into the upper atmospher. They looked like upside-down comets.
The northern lights are caused by the solar wind. In addition to electromagnetic radiation (light, heat, UV, etc.) the sun also emits charged particles. This stream of ions is known as the solar wind. Much of the wind is channeled away from the Earth by its magnetic field. The portion that makes it through is directed to the poles. When the ions strike the upper atmosphere they excite electrons in the gases causing them to emit light.
Amidst all these (very good) links, a book plug: I greatly enjoyed “The Northern Lights” by Lucy Jago (ISBN 0-375-40980-7), a fine example of a genre I really like. It’s the story of the Norwegian scientist Kristian Birkeland, concentrating on his efforts to understand the Northern Lights. There’s enough science in the book so you can learn something, with enough background and “colour” that it reads more like a detective novel than a popular science book, communicating the excitement of science.
The “photo of the month” shown at http://www.northern-lights.no/zope/Contest/Month/?monthly=2002_04 (thanks for the great link, KneadToKnow!) is stunning. As a light-polluted-urbanite, all I’ve ever seen is some not-very-exciting luminous organ-pipe shapes in the sky.