This photo has been making its way around Facebook recently with descriptions like "The Pacific Ocean, Atlantic Ocean, Chile, Argentina, Uruguay, Paraguay and in the background the silhouette of the moon. Photo taken from the international space station"
But there's never a source posted. One should always find out if a photo has been presented as real by a reputable source before spending time defending it. For example, this photo, is found on NASA's site and shows much less Earth curvature and a much smaller Moon.
Older copies turn up on social meda, but never have a source (except for other social media). For example, here's one on Pinterest that links to Taringa, where there's no info about where it came from.
I also found a few articles, in both English and Spanish, containing this image. These sites look like the sort that have cheaply (or perhaps automatically) generated content. Top photos of Earth from the International Space Station, The best photos of Earth from the International Space Station, Las mejores fotos de la Tierra desde la Estación Espacial Internacional all credit this photo to "NASA / DegreaseNeil"
This Reddit thread includes a comment that says that "DegreaseNeil" was a fan account in Twitter, the link there goes to a now-deleted account. But no links to either source. But there's a hashtag #DegreaseNeil at Twitter that contains some more info.
In short, always insist on a link to a NASA website.
