Four more Galileo-satellites enter space

The amazing things Sentinel satellites see

The story so far

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.

The amazing things Sentinel satellites see

In spectacular true color

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.

The amazing things Sentinel satellites see

In spectacular false color

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.

The amazing things Sentinel satellites see

Harbor under threat

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.

The amazing things Sentinel satellites see

The 'Yuma checkerboard'

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.

The amazing things Sentinel satellites see

Tracking change in the Aral Sea

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.

The amazing things Sentinel satellites see

Meanwhile, Back in Berlin…

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

Author: Zulfikar Abbany