The last time the Nile turned red, according to the biblical story of Moses, God had just started showering Egypt with the 10 plagues. This time, however, it's thanks to a satellite that can measure infrared energy - and writers at the Times of Israel tell us more:
A newly released satellite image of Egypt’s Nile river shows the river colored deep red, bringing to mind the biblical first plague in which the waters of the great river turned to blood.
But, this time at least, it is not the wrath of God that is responsible for the river’s crimson hue: The European Space Agency’s Sentinel-3A satellite, which took the picture, uses a radiometer to measure infrared energy.
The heat radiated by vegetation around the river is therefore responsible for the red color...
The satellite will be able to spot upcoming droughts by detecting subtle changes in surface color that suggests crops are failing.