This might sound cheesy, but I find it incredible that we live on a planet that is so very small on the cosmic scale, but so big on a human scale. How insignificant we are, yet how important our actions are on a human scale.
Also, I found this image while searching for a space picture for my business card (custom-made here). I was looking specifically for images of the Earth seen from space. I honed in on this one and wanted to find out where the original was. As it turned out, many many people had reposted it without citing the source. I eventually used tineye to hunt down all instances of this image on the internet, to bring you the source that the photo is linked to above.
I’m still not sure whether I have permission to use this on a business card. I read their image use guidelines, but I couldn’t figure out whether this would count as “advertising” or not, so I emailed the contact on their advertising guidelines page. I’ll update this page when I hear back from them.