If you want the stars to show you put the shutter speed up to 20-30 seconds. Thats how long the camera will be capturing light. It was hard to get the stars tonight because the moon just drowned out all of their light. To get the brightest image possible you would up the ISO lower F-stop and up the shutter speed but usually it is a good balance between those.

 probably a bit much of an explanation for someone who doesn't know cameras well but thats what goes down. We are going to try to get some epic mountain biking shots with this kind of stuff in the background tomorrow.

 I'm no camera expert, but if you want stars to show, do you ramp up the exposure?
moon is hell bright tonight as well