It's that time of year — the Earth Observatory is pitting gorgeous photo against gorgeous photo in a tournament to pick the best of 2013. Set up a betting bracket, then vote the best photos in each of 4 categories.
Need more enticement to spend your Monday afternoon eyeballing the Earth? Here's a few of my favourites (...not to bias the voting or anything...)
Need yet more eyecandy? Here's last year's winners.