On the eve of the launch of The Multiversity, the nine-issue miniseries by Grant Morrison, Ivan Reis, Joe Prado, Chris Prouse, Karl Story, Ben Oliver and Frank Quitely, the information is kind of slim: You can hover your cursor over just three Earths -- Earh-0, Earth-8 and Earth-23 -- to get details, but DC states, "New Earths are being revealed frequently so visit often."
Of course, we already know many of the Earths depicted on the map, conceived by Morrison and designed by Rian Hughes. There's Earth-26 for Captain Carrot, Earth-18 for the almost forgotten Western heroes of the 1950s and '60s, Earth-43 for vampire Batman and his kind, and so on. And Earth-8, described only in vague terms on the DC website? According to USA Today, it's for Marvel superhero analogs.
Seven universes, however, are labeled as "unknown." "I thought it was only fair to leave those for other people to tell stories in the future," Morrison tells the newspaper.