This is an unusual picture â€“ it's a radar image. You need to look carefully to interpret what's there.
The Mediterranean is easy to pick out, and Barcelona is a major seaport, so you can find it on the right. There is another city centre-left, which is Lleida. To the south of Lleida is part of the Ebro River. The dark water is prominent as dams back up the water flow. It eventually empties into the Mediterranean, but the Ebro Delta isn't in the picture. The rugged-looking area at the top of the image are foothills of the Pyrenees. Blue-green areas on land are cultivated areas.
Here is a picture of the Dead Sea, the lowest elevation on the surface of the Earth. The bit with water looks like a Sapphire jewel amid the dead surroundings. The picture was taken by ESA astronaut Samantha Cristoforetti.
Now here's something you don't see every day, even if you're on the International Space Station. NASA astronaut Terry Virts saw - and photographed - the Great Pyramids of Giza on the very last day of his tour.
ESA's Sentinel-1A Earth-observation satellite captured a radar image of central California. The San Andreas Fault shows up as a nearly straight line. You can see the San Joaquin Valley to the east and the foothills of the Sierra Nevadas beyond that. The valley has been known as one of the most productive regions of the USA, but has been bedeviled by drought in recent years.
ESA's Copernicus programme is developing data sets for Earth monitoring, using their Sentinel satellites. Here is a recent image from Sentinel-2 of Sardinia, Italy. All of the red is surprising for such an agricultural island, but in this false-color image shades of red are showing vegetation.
ESA's Sentinel-1A took this picture of the Antarctic a Peninsula and it's a real beauty. I wondered if it should go on the Heavenly Art page.
You have to remember that the colors aren't what we'd see with our eyes. The Sentinel program is for Earth observation and is acquiring a database of land use. This image is a radar map. Land, ice and water reflect the signal differently and the colors show this.
Here's a brand new picture of our home taken from a million miles away. It's from NASAâ€™s new Earth Polychromatic Imaging Camera (EPIC) which is positioned at Lagrange point L1. (This is a place where the gravitational pull of Earth and Sun are balanced out.)
The instrument can image in ten channels from the infrared through to ultraviolet. This picture will help to calibrate the instrument to remove some of the blue atmospheric haze â€“ pretty in this picture, but not so good for atmospheric monitoring and providing early warning of geomagnetic storms.