Landslides and avalanches are the most dramatic, sudden, and dangerous examples of earth materials moved by gravity. Landslides are sudden falls of rock, whereas avalanches are sudden falls of snow.
        
             
        
        
        
The first people to be called English were the Anglo-Saxons
        
             
        
        
        
NASA satellite observations and citizen science helped build a database called HIVE-OS to help local businesses understand variables like soil moisture and plants that affect honeybee health.