Taking two to four days to reach the earth, the sun's solar winds and magnetic particles strike the magnetosphere like a shockwave, causing the hauntingly beautiful aurora borealis lights. Another great site from exploratorium.edu, Auroras: Paintings in the Sky showcases these northern lights, offering the lay person a good introduction to this mysterious phenomenon. The site has six sections: what aurora's look like, what makes them happen, what their solar connection is, where you can see them, what they look like from space, and why they are different colors. Each link provides non-technical descriptions and incredible photographs, illustrations, and movies of auroras that make the site enjoyable and educational.