Did you watch the Landsat 8 liftoff today? 

It saw the Landsat-8 mission hurtle skywards on an Atlas rocket from the US Air Force base at Vandenberg shortly after 10:00 local time (18:00 GMT).

The spacecraft will maintain the longest continuous image record of the Earth’s surface as viewed from space. It is a record that now stretches back over 40 years - an invaluable tool for studying our changing world.

The latest spacecraft was lifted by the Atlas into a 680km-high polar orbit. It will take about three months for Nasa engineers to test the platform and get it ready for use at its operational altitude of 705km.

“Landsat is a critical asset,” said US space agency (Nasa) project scientist Dr Jim Irons. “land.

“In order for us to adapt to these changes and make sensible decisions about what we do to the surface of the planet, we need the information this satellite series gives us,” he told told BBC News.

The entire 40-year image archive is open and free. Scientists around the globe exploit the information in myriad ways - from monitoring the health of crops and the status of volcanoes, to measuring the growth of cities and the extent of glaciers.

One of uses best known to the general public will be on their phones and computers through Google, which incorporates Landsat data into its Earth and Maps applications.