Today's Astronomy Picture of the Day is striking. However, should I be concerned that I spotted which of the two pictures was Earth without a moment of hesitation? It does make the point quite nicely that Earth is a varied planet and that it is unreasonable to categorise any other planet from one or two shots (Ice Planet Hoth or Forest Moon of Endor, anyone?).
Stargate SG1 once showed this very well by having Carter and O'Neill wind up in Antarctica, and Carter reports back 'Colonel? It's an ice planet. That's all there is as far as the eye can see. No chance.'. (Season 9 of SG1 is now filming).