Now on ScienceBlogs: Oldest Human-Made Object in Space

ScienceBlogs Book Club: Inside the Outbreaks

Built on Facts

An exploration of physics and the quest to understand our world.

Profile

profile.jpg Matt Springer is a graduate student of physics at Texas A&M university. He is also an occasional writer and tinkerer, and he is probably too curious for his own good.

Search

Twitter

Yes, I've joined the horde. @BuiltOnFacts. Follow if you'd like!

Donate

Help Matt not starve! Use this link to amazon.com when you order from Amazon, and a fraction of the purchase price will be sent to me at zero cost to you. Much obliged, and thanks for your patronage.


Recent Posts

Recent Comments

Archives

Physics/Math Blogs

My Other-Than-Physics Reading (variable, very incomplete)

« Singing in the Rain | Main | Backyard Lightspeed »

Iridium!

Posted on: April 9, 2009 10:00 AM, by Matt Springer

I have a project for you, since I know practical physics is pretty popular around here. This one involves orbital dynamics, optics, and astronomy. The required experimental apparatus is just your eyes, a clock, and an internet connection.

There are these satellites orbiting overhead by the name of the Iridium constellation, working diligently to provide various communications services to its customers. We're not so interested in that. What we are interested in is the fact that these satellites have highly reflective mirror-like antennas which reflect sunlight down to the earth. With a little geometry done for you automatically online, you can predict exactly when these beams of reflected sunlight will intersect your position. Some of them are bright, in some cases many times brighter than the brightest stars. All you have to do is input your position, set your watch to the next flare, and walk outside to see it.

It seems pretty trivial, but it's quite a demonstration of the power of physics that such an event can seem trivial in the first place. Give it a shot, I promise it's really cool.

Share on Facebook
Share on StumbleUpon
Share on Facebook
Find more posts in: Physical Science

TrackBacks

TrackBack URL for this entry: http://scienceblogs.com/mt/pings/106113

Comments

1

i think i saw one by accident a couple weeks ago. i was walking my dog at night, looked up hoping for a meteor and saw a *bright* satellite. it faded then brightened up again about a minute later, then faded out completely. i was told it was probably an iridium flare. very cool.

Posted by: rob | April 9, 2009 10:28 AM

2

I've been viewing the iridium satellites, with the help of heavens-above.com, for a couple of years now. It's fun showing them to the kids in the neighborhood. The adults enjoy it as well.

Posted by: Tom S. | April 9, 2009 10:50 AM

3

whoa thank you!! this is probably the coolest thing i've seen this week :P

Posted by: joulesm | April 9, 2009 10:56 AM

4

OK, if the clouds actually clear in SE Michigan, i'm definitely gonna do it...

Posted by: PalMD | April 9, 2009 11:12 AM

5

I've got a -7 mag flare coming up at 03:30 Friday, and a holy crap! -9 on Saturday at 06:30. Yowza!

Posted by: magista | April 9, 2009 5:39 PM

6

Just got back from capturing a magnitude -7 event. Thanks for the referral! It was a cloudy evening, but the light cut through the clouds and we were able to capture this image:
http://twitpic.com/32yg2
http://twurl.nl/wrk462

Polaris was visible just to the left of the event, so it was easy to set up the shot beforehand. Undoubtedly the coolest thing I've seen in a while.

Posted by: scott | April 9, 2009 11:24 PM

7

Is there something wrong with the Heavens-Above.com website since about 8 April 2009??? Every time I try it, I get "Connection Interrupted
The document contains no data."

Posted by: pkoen | April 11, 2009 4:58 AM

8

Now we just need someone to write an iphone App for this...

Posted by: joulesm | April 13, 2009 1:39 PM

Post a Comment

(Email address is entirely optional, but a consistent email - fake is fine - helps the system identify repeat commenters as not spam.)





ScienceBlogs

Search ScienceBlogs:

Go to:

Advertisement
Follow ScienceBlogs on Twitter

© 2006-2011 ScienceBlogs LLC. ScienceBlogs is a registered trademark of ScienceBlogs LLC. All rights reserved.