In my job at the European Space Agency, we look at what satellites can do for non-space sectors of society. Sometimes, however, you simply have to stop what you do and enjoy the majestic beauty of some of the images we get!
In this series, I share some of my favorite images I have come across in the last weeks together with a short explanation of what you are seeing in the image. I hope you will enjoy them!
Ul'banskiy Bay, Russia
The Ulban Bay in eastern Russia seen by the NASA Landsat Satellite
Image credit NASA observatory
The Ulban bay in eastern Russia is often referred to as the “Bay of whales”. Here, the Bowhead and Beluga whales come to find food during the summer. As ice tends to stay until June, the waters are fairly untouched once it recedes. The whales then collaborate in driving fish into the freshwaters of the bay.
As you can see in the image, the area is not inhabited by people. Instead, lakes, rivers and marches are allowed to dominate the lower parts of the bay which quickly
What makes this image so beautiful to me is the different layers of colours, both in the sea and at land. On land, the colour of vegetation changes as the high difference in altitudes favours different types of trees. At sea, the early frost along the shore creates a grey colour fading into a lighter blue.
I highly recommend watching the image in its highest resolution here as it is truly spectacular.
The island of Tongatapu, Tonga Kingdom
The Island of Tongatapu in the Toga Kingdom in the southern Pacific Ocean
Image credit ESA
The Tongatapu Island is the biggest of the 169 islands of the Tonga Kingdom. The kingdom is found south-west of Fiji and north-east of Australia and New Zealand in the southern Pacific Ocean. Roughly 70% of the Kingdom’s population lives on this main island. The Kingdom’s capital, Nukuʻalofa, can be seen at the centre of the northern coast, along the anga’uta Lagoon.
Looking closely at the island, you can see that much of it is covered by farms seen as numerous green rectangles. The island consists mostly of fertile soil on top of limestone and volcanic ash that stems from surrounding islands.
What makes the image so beautiful are the coral reefs to the north of the island. Satellites images are frequently used to study and monitor coral reefs like these to detect coral bleaching. These occur when algae is expelled from the reeves due to high temperatures in the water. With global warming, the bleaching occurs ever more frequently, threatening coral reeves like this with starvation.
This can have large costs to communities such as these, whose reef ecosystem is essential for fisheries, regional tourism and coastal protection.
Another thing worth noticing is how different the colours of the waters are. Ranging from green, to dark and light blue, to nearly black, all depending on the chemistry of the waters. Clearer waters reflect less light back into space, making them appear almost black in satellite images.
Bajestan, Iran
Bajestan in Northeastern Iran together with the surrounding mountains, barrens and farms
Image credit ESA
My favorite image of this round's satellite images is this 10-meter resolution image of northeastern Iran.
Although most of the image consists of barren lands, you can see the small city of Bajestan at the very right end of the image seen as a gray square. The red squares to the left of it, and scattered across the image, are farms. They appear red due to the false-color processing which adds an additional layer of color from the electromagnetic spectrum that is otherwise invisible to the human eye. As chlorophyll-rich plants emit more red light, vegetation turns red when this layer is added on top of the image, allowing us to quickly spot a number of farms scattered across the land, in particular to the north of the city and in the bottom left corner. The city also turns grayer as there is no color in that part of the electromagnetic spectrum reflecting off pavement and rooftops.
Most of the image is of mountains and barren lands, which is typical for an Iranian landscape. In the center and upper left corner of the image, you can see alluvial fans stretching out across the plains. These come about over time as streams of water flow down from the mountains and enters the flat plains. You see some stark differences in the colors of the landscape due in part to salts that are carried down with the streams and left in the fans.
I really love this image because of the way in which the stripes look almost like the strokes of a painting brush, giving the image the look of a painting, rather than a satellite image.
Want to try processing new satellite images yourself?
Most of the images in this series are taken by the European Sentinel satellites. Most images have also been processed by ESA, the European Space Agency. You can download the raw data from their satellite constellation yourself for free here, which can be processed professionally by the free and open source tool snap. You can also browse new satellite images online for free using the EO Browser.
