What causes earthquakes?

Related: Technology & science

1. Headlines
   1. NASA unveils Grand Challenge to hunt asteroids

      NASA's latest "Grand Challenge" is a biggie: Can you think of better ways to find potentially threatening near-Earth asteroids and do something about those threats?

   2. Facebook may add videos to Instagram, rumors suggest
   3. Last telegraph shuts down in July but some say "Don't. Stop."
   4. Facebook is down for some users
   5. Catherine the Great, Tchaikovsky letters returned
   6. Sally Ride and Neil Armstrong: Space icons honored
   7. NSA may stop vacuuming Americans' phone data
2. Multimedia
   1. 
      Video
      30 years ago: Sally Ride’s journey into space
   2. 
      Video
      Recalculating! GPS may lead you astray
   3. 
      Video
      Surveillance prevented at least 10 U.S. terror attacks, NSA says
   4. 
      Video
      From the Archives: Sally Ride becomes first American woman in space