Purpose:  Get a feel for image size and scale, and Determine what Andromeda is.
 

Go to the site  http://skyview.gsfc.nasa.gov/docs/easy.html

Enter Andromeda into the space for required parameters, check optical for your survey
and go down and change the image size to 3.00 degrees by 3.00 degrees. (its a pull up
menu). It will take a second to come up.

What do you see, describe the image?
Can you pick out the Andromeda?
How big is the Andromeda?

Go Back and change the size to .3 degrees by .3 degrees.

What do you see?
What is Andromeda?
How big do you think it is?

Go Back and change the size to 1.0 degree by 1.0 degrees.

How much of the window does the picture take up now?
How big do you think the Andromeda is?
What is Andromeda?

What did we change by changing the image size?
What is special about Andromeda?

Overview of Activity:
Andromeda is the closest galaxy to the Milky way and it too is a spiral galaxy. It is one of
the few galaxies actually moving towards us, so it actually has a blue Doppler shift. By
changing the image size we changed the amount of the sky we were looking in the same
window size so the image took up more of the image as we decreased the image size.  As
an additional activity it may be a good idea to have the students do a little research into
galaxies their size, properties etc. to supplement the activities.