Wow! That's gorgeous! I've looked at pics taken of the aurora borealis in Alaska. I wondered if it would be possible to duplicate such vibrant colors in soap. I did attempt a batch but the colors weren't vibrant enough.
Someone did do a batch that looked like the Aurora Borealis. It was gorgeous! It was mainly black with vibrant colors swirled through it. It might have been My Nature's Art but I'm not positive it was her. I should have kept a link to it.
No, it wasn't on this forum. I'm positive I saw it in a video so it must have have been on youtube. But please don't hold me to it. I'm not positive who did it but here's the link to her channel if you'd like to look. http://www.youtube.com/user/MyNaturesArt
I've not had huge success in making a northern lights soap, altho I have tried a few times. The best results for that sort of effect were when I felted some bars of soap using those colors. Pretty labor intensive, but I could get the colors right and the randomness.