This image shows where the Rio Negro and the Solimões River join up to form the Amazon River.
The Rio Negro is the Amazon’s largest tributary, flowing for 2300 kilometres from Colombia. It is also the world’s largest black-water river, getting its color from decayed leaf and plant matter.
The Solimões River, in stark contrast, gets its lighter colouring from rich sediments including sand, mud and silt. It flows for about 1600 kilometres before meeting the Amazon at this juncture.
Because of different temperatures, speed and water density, the two rivers flow side by side for a few kilometres before blending together.
On the north bank of the Rio Negro is the Amazon basin’s largest city, Manaus, with the Adolfo Ducke Forest Reserve to its northeast. Named after the botanist Adolfo Ducke, the forest is a protected area for biodiversity research.
The aerial image was captured by the Copernicus Sentinel-2, a two-satellite mission. The satellites both have high-resolution cameras that image the Earth and can help track changes in land cover and inland waters.