Nasa launches satellite to observe soil moisture

Nasa has launched an Earth-observing satellite, which will measure the amount of moisture in soil.

The Delta 2 rocket launched from Vandenberg Air Force Base in California.

Nasa hopes the data collected from the three-year mission will help scientists to monitor droughts and improve flood forecasts.

The Soil Moisture Active Passive (SMAP) observatory's instruments will be turned on 11 days after launch.