Space Invaders!

So I'm doing this pre-test on the internet in an attempt to study for my astronomy final tomorrow. I started with the chapter I know best so I wouldn't get discouraged. But alas, I only got 50% on it. So, I decided that astronomy games would be more beneficial and I found an awesome online version of Space Invaders which I haven't played for years and I thought it was cool so I'm posting about it.