Here’s a problem that probably hasn’t occurred to you: A lot of space aliens might have difficulty becoming a spacefaring species. Michael Hippke, an affiliate at Germany’s Sonnenberg Observatory, explains the problem in a new paper.

Facebook is adding a dating layer to its main mobile app, CEO Mark Zuckerberg announced today during the company’s F8 developers conference keynote in San Jose, California.

Two years ago, when Twitter was fielding acquisition offers, Disney (DIS) considered buying it, Disney CEO Bob Iger revealed this past October.