I guess it's a real eclipse, which makes it an unusual subject, but not really a very interesting photograph. I know my "ho-hum" reaction does not do justice to the significance of the thing, but have you seen the photograph of Hillary standing atop Everest? A very significant moment, yet it still looks like nothing more than snap of a skinny guy in goggles on a snowy hill. Ironic, isn't it ... you've taken a good photograph of the ultimate manifestation of darkness, and I'm unmoved. Sorry! 5 (On the "bright" side, 5 is better than my own darkness image is doing!)
In it's simplicity, I actually find this photo interesting and stimulating. I'm not a big stickler for having to 'obey' the rule of thirds, but I'm wondering if maybe this would be even a stronger presentation if the subject were placed at the upper right thirds intersection? Perhaps not. I do like the image.
nice and simple....the dark is dark! I wonder how the photo would have looked with a different crop---having the quarter moon nearer to the right upper corner...just a thought---you could try it one day. I am scoring you high for taking a difficult photo.