Subreddit Stats - Statistics for every subreddit.
NASA Exoplanet Posters - Imagine visiting worlds outside our solar system
Redective - Find information about Reddit users
Astronaut - You're an astronaut. Click to watch random videos in space.
FrontPageMetrics - Daily updated statistics for every subreddit on Reddit. Top subreddits, new subreddits by date, all subreddits, trending subreddits, plus more Reddit stats
The Size of Space - An interactive visualization of the universe