TWTR: Shares of Twitter opened this morning at $45.10, nearly $20 higher than the offering price of $26, or $18.1 billion for the entire company. The 140-character message service has become a player in personal relationships, politics, even war. But, …

Meteorite Hits: What appears to be a meteorite has hit western Siberia, injuring more than 700 people, most by breaking glass. At least several witnesses captured the event on video, which included a loud “boom” as the burning object struck. …