Documents Today is Monday, April 20 th, 2015 Pre-Class: How long is a year? What causes the seasons? ...

Slide 1 Today is Monday, April 20 th, 2015 Pre-Class: How long is a year? What causes the seasons? http://deepskycolors.com/pics/astro/2011/11/mb_201 1-11_Aries.jpg Dust…