Mysterious tremors on the moon have been traced back to an unexpected source

• Data showed a mysterious quake happening every lunar morning, and scientists weren't sure why. 
• A new study has found morning tremors are coming from the Apollo 17 lunar lander base.
• The lander base expands and vibrates every morning as it gets heated by the sun.

Scientists baffled by mysterious daily quakes on the surface of the moon have traced back their origin to an unexpected source.