ET search: Look for the aliens looking for Earth User IndiaMars, in the Astronomy subreddit, 02 Mar 2016
ET search: Look for the aliens looking for Earth (X-Post /r/astronomy) User Hat3d1312, in the Aliens subreddit, 01 Mar 2016
ET search: Look for the aliens looking for Earth -- astronomers propose hunting for civilizations on worlds that can see our planet cross the Sun. User filosoful, in the Astronomy subreddit, 01 Mar 2016
ET search: Look for the aliens looking for Earth -- astronomers propose hunting for civilizations on worlds that can see our planet cross the Sun. User filosoful, in the /r/space: news, articles and discussion subreddit, 01 Mar 2016
ET search: Look for the aliens looking for Earth User rabidoverlord, in the Extraterrestrial Biological Entities subreddit, 01 Mar 2016
ET search: Look for the aliens looking for Earth - Astronomers propose hunting for civilizations on worlds that can see our planet cross the Sun. User anutensil, in the scifi subreddit, 01 Mar 2016
ET search: Look for the aliens looking for Earth User KingWord, in the Technology subreddit, 01 Mar 2016