Unable to open Sketchup program

I just down loaded the Sketchup program to my Mac. It installed into my applications folder, but when I went to open it, there was the "no " symbol over top (circle with line through it. Any help would be appreciated.

Nevermind. I discovered the problem. I need an updated version of my computer to run the program.

For reference by other who may see this topic, your profile says you have OS X 10.6.8. SketchUp 8 was the last version of SketchUp that supported that OS version.