A STRANGE light spotted in the skys earlier this week is understood to be a NASA rocket and satellite which is monitoring the earth's landscapes.

Many people across Essex spotted the white light moving in the sky last night and questioned what it was.

It is likely that what they saw was the Atlas V rocket leaving the atmosphere carrying a Landsat 9 satellite into orbit.

Landsat 9, a NASA satellite built to monitor the Earth’s land surface, successfully launched at 2.12pm EDT - 6.12pm in the UK - on Monday from Vandenberg Space Force Base in California.

A joint mission with the U.S. Geological Survey (USGS), Landsat 9 lifted off on a United Launch Alliance Atlas V rocket from Vandenberg’s Space Launch Complex 3E.

“NASA uses the unique assets of our own unprecedented fleet, as well as the instruments of other nations, to study our own planet and its climate systems,” said NASA Administrator Bill Nelson.

“With a 50-year data bank to build on, Landsat 9 will take this historic and invaluable global program to the next level.

"We look forward to working with our partners at the U.S. Geological Survey and the Department of the Interior again on Landsat Next, because we never stop advancing our work to understand our planet.”