The amazing things Sentinel satellites see

It may be among the strangest places on Earth, but this is where a lot of the European Union's Sentinel satellite equipment is being built for the Copernicus Earth Observation program. In Cannes, Thales Alenia Space is responsible for the Sentinel-1 satellites and a few of the others, too. The contractors include Airbus and many more. Sentinel-1B launches this week, making the first mission whole.

Sentinel-1A was the first to launch on April 3, 2014. Since then, two have followed - Sentinel-2A on June 23, 2015 and Sentinel-3A on February 16, 2016. This shot from Sentinel-3A is one of its earliest. It shows the River Nile and Delta and parts of the Middle East. Using a sea and land surface temperature radiometer (SLSTR), the satellite measures the energy radiating from Earth's surface.

This incredibly sharp image shows Red Sea coral reefs off the coast of Saudi Arabia. It was captured by Sentinel-2A on June 28, 2015. The quality of the Sentinel images is a vast improvement on previous satellite missions, such as Envisat. The Sentinel-2 mission is for land monitoring. It provides images of vegetation, soil and water cover, inland waterways and coastal areas.

This false color image of south Khartoum in Sudan was one of the first from Sentinel-2A, captured five days after it arrived in orbit. In the top right corner you can see a bit of the Blue Nile River. The scattered red blotches along the river banks indicate dense vegetation, which is one of the things the satellite monitors. It's a false color image, as color was added to aid interpretation.

This is another great shot from Sentinel-2A, showing Sierra Leone in West Africa. The country's capital, Freetown, is on the peninsula at the bottom of the image. Its economy depends on the natural deep water harbor. But ESA says the estuary is "threatened by a growing population [and] unauthorized housing development," which has caused the removal of many hectares of mangrove vegetation.

Many of the Sentinel images are like works of art. You don't really have to know what's going on to appreciate them. But scientists, policymakers and authorities charged with national security rely on satellite imagery. And given the tools and skills, normal folk can benefit too. The Copernicus program is driven by a principle of Open Data. This shows Yuma in southwestern Arizona.

This is the Aral Sea as captured by Sentinel-1A. It's a composite of three radar scans taken between 2014 and 2015. ESA says the Aral Sea is a "striking example of humankind's impact on the environment and natural resources. [...] It has lost around 90 percent of its water volume since 1960 because of Soviet-era irrigation schemes." The different colors show the changes between the scans.

Captured by Sentinel-2A, this image shows a vibrant Berlin, the German capital, in exquisite detail. It shows how green the city is, with the Tegeler See and Wannsee on the western side. There's also the former airport, the Tempelhofer Feld, in the lower center of the image, which in summer blooms with people, kites and bikes. All these images can be seen in full: www.esa.int/spaceimages/Images