For starters, I think your piece, Aurora Borealis, is eye-catching and original. I like the beautiful, children's book simplicity in this piece and the colors are simply beautiful.
However, I do thin there are a couple areas that could be improved. First, the father is sitting awfully close to the tent and the tent shows no indentations at all. I think it would be better to place the father a little farther away from the tent.
Second, I think it might be interesting to see more color in your aurora. While a quick Google search did show photos of monochromatic aurora, I think the message might come more strongly if there was more color. That, or if you were to play with the shape of your aurora. But I'll add that I think my first suggestion is a little more important.
Overall, you've created a nice work of art and I'm glad you decided to post it on deviantART for everyone to see. I think the Internet could use more art like this.