Friday, November 17, 2006

Things Far Greater than You or Me

Aurora borealis. Watched a documentary on the northern lights and was awe-struck.

The lights are caused by the collision of charged particles in the Sun's solar wind with atoms in the Earth's upper atmosphere. The collison energizes the gases in the atmosphere, which then converts this extra energy to light.

Apparently the best times to catch these lights are during winter in the northernmost regions - if you're here in the U.S., that would be Alaska, from Sept/Oct to Feb/March.

Another addition to the "to-do" list. Better move this one up higher - braving the cold of wintry Alaska sounds like it takes a little brashness of heart. :)
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Did you know that Nov 17-19 of each year is the best time to view the Leonids? The who, you say? It's an annual meteor shower from the comet Tempel-Tuttle.

Here's what I learned:

A comet is a "small" body in the solar system composed of rock, dust, and ice. They orbit the Sun, and can have a "coma" (atmosphere) or a tail, both of which are effects of the sun on the comet body.

Each time the comet swings by the Sun, the interaction produces small particles that spread out along the entire orbit of the comet. This is called the "meteoroid stream." As we also orbit the Sun, if the Earth's orbit intersects with a comet's orbit, the Earth passes through the meteoroid stream at roughly the same time each year. We Earthlings see the intersection as meteor showers.

Meteor showers appear to "radiate" from one point in the sky. They are named after the constellation that the radiate from - hence, the Leonids radiate from the constellation Leo.

Why do they seem to radiate from one point? Because of our viewing perspective. Think of it this way - if you stand in the middle of a railroad track and follow the rails as far as your eyes can see, the tracks seem to converge to a single vanishing point on the horizon. Which you know is impossible, because the tracks are parallel. Perspective, my friends. So meteor particles travel their orbit at about the same velocity in parallel paths, and from where we stand, they look like they start at the same point in space.

These meteor particles enter our atmosphere at high speeds, creating the streak of light that we see. Most of the particles are very small and burn up long before reaching the earth's surface. The larger pieces that do reach the earth's surface are called meteorites.

Very cool, huh? Astronomy is such a fascinating field...

11 Comments:

Blogger ipanema said...

I love these 'heavenly phenomena'. They never fail to leave me dumbfounded at times. Simply beautiful! And you're right about Astronomy. :)

2:32 AM  
Blogger always learning said...

Hi Ipanema! A friend of the family is an astrophysicist for NASA and just talking to him about his job was awesome... he gets to study stars for a living!

2:48 PM  
Blogger TheTundraPA said...

Beautiful northern lights photos! It is amazing to stand under them and feel the energy. I hope you do make it to Alaska in the winter and get to experience them. The key is warm gear. Book a few days at the Bettles Lodge in Bettles, AK for an awesome aurora experience.

11:38 AM  
Blogger always learning said...

Hi Tundra PA,
Thanks for the recommendation - I was just surfing the web yesterday to figure out where to stay :)

8:08 PM  
Anonymous Anonymous said...

Linked to your blog via Tangled Bank; congrats!

Thanks for the mention of the Leonids and the background information.

Do not forget next month's Geminids.

BB

9:47 AM  
Blogger cdemby said...

Hi there.... found your site as I was wandering the web looking for fabulous northern lights and auroras. And - when I saw the Aurura-Borealis.jpg I just flipped, and wondered if you have the source information as to where you found that wonderful picture?

I compose cosmic electronic music and this image would be so perfect for the cover of my next album. The website is
http://www.constancedemby.com and you can reach me directly at cdemby@constancedemby.com

also, I'm really enjoying your blog...! and the tasteful images you select...

I'd so appreciate hearing from you!

God bless....
Constance Demby
http://www.constancedemby.com
cdemby@constancedemby.com

11:07 PM  
Blogger always learning said...

Hi Constance!

Welcome, and thanks for reading!

The pictures are usually from a google search, and usually have a "photo credit" link at the bottom of the post if they aren't my own... If you click on that link it'll take you to where I found it. Hope that helps, and good luck with your next album! :)

12:21 PM  
Blogger somethingsmissing said...

hey!
i love the aurora so much,but i have school so i can't really see the best auroras, so i make it up by finding great pictures.these pictures,well most of them, are awesome!my faves are the houses w/ auroras behind them. here is a link to some REALLY good pic's.they might be better than the ones you already have. www.spacew.com/gallery/image005664.html
hope it works!

11:24 AM  
Blogger Arya said...

Beautiful! The auroras never fail to captivate me!

8:40 AM  
Blogger silfiriel said...

The only thing that's wrong with aurora borealis, is that it's not apearing all over the world. but there's Aurora australis, that appears on the south pole. So I found some great hi-res pics of borealis at http://adventurelogger.blogspot.com/2007/12/aurora-borealis-northern-lignts.html

1:48 AM  
Blogger wandering visitor said...

hi somethingsmissing, arya, silfiriel!

thanks for visiting, and thanks for the great links - beautiful pictures!

7:18 PM  

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