Really The Great Wall of China can be seen from space? Although it is one of the most common beliefs among society, the answer is no. And it can’t be seen because, although it is really long (more than 21,000 kilometers, at least, including all its tributaries), it is too narrow to stand out in the midst of the rugged terrain in which it is located. Moreover, anything directly made by humans is not easy to appreciate from space.
The most visible artificial structure when viewed from Earth’s orbit is in Spain. This is Almería’s ‘sea of greenhouses’, located around the town of El Ejido. This is the region with the highest density of plastic crops in Spain and can be seen from the International Space Station (ISS) with its bright color.
Located in the Campo de Dalías region, where El Ejido is located More than 20,000 hectares of land devoted to greenhousesAccording to the 2020 Agricultural Census, the area in the entire province of Almería is 30,000 hectares, which represents almost half of the areas in Spain, i.e. approximately 65,000 hectares, according to data from the National Institute of Statistics (INE). The figure for Almería may be even higher because, according to the latest data (2021) of the Junta de Andalusia, the agricultural area covered with plastic in that state reached 32,000 hectares at that time.
Approved by Pedro Duque
It is one of the largest concentrations of greenhouses on the entire planet, making it easily and precisely distinguishable from space. In fact, this was confirmed by a Spaniard who arrived there recently: Former Minister of Science and Innovation in the Government of Spain and astronaut Pedro Duque.
When asked on TVE’s ‘Desafía tu mente’ program whether the Great Wall of China could be seen from space, the astronaut categorically denied: “This is a wall that is not very high, made of the same materials as the Great Wall of China. the land surrounding it. There are people who say they know where it is and took photos there, but they don’t know.”. In fact, the first Chinese astronaut to photograph it from above admitted that it could not be seen with the naked eye.
But what is clearly visible from the International Space Station (and photos taken by NASA confirm this) is something that exists on the Iberian Peninsula: “The most visible thing is Greenhouse field in the south of Almería, this is what you see from around the world”. This is possible due to its large extension, but also its high capacity to reflect sunlight intensely.
In fact, a NASA publication from two years ago recalls that these Almería greenhouses “covered such a large area that the white roofs reflected a significant amount of light, possibly even causing a local cooling effect.” .
High reflectivity of greenhouses
Using observations from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on NASA’s Aqua and Terra satellites, researchers at the University of Almería calculated that Almería’s surface albedo increased by almost 10 percent between 1983 and 2006 due to the high reflectivity of the greenhouses. They concluded: probably contributed to a cooling effect of 0.3 °C per decade in Almería That compares with an increase of 0.5°C per decade in the region.
According to some estimates, Almería’s greenhouses now produce between 2.5 and 3.5 million tons of fruits and vegetables annually; This is enough to be an important source of out-of-season tomatoes, peppers, cucumbers and melons for residents throughout Europe.
The spread of such facilities is also the subject of debate. impact of plastic waste those that come out of greenhouses and reach either land or the sea.
The sea of greenhouses of El Ejido This isn’t the only human creation visible from spaceBecause southeast of Salt Lake City (USA), you can also see the Bingham Canyon mine, the largest human excavation in the world. According to astronauts, China’s Three Gorges Dam on the Yangtze River or Dubai’s Palm Jumeirah, built at sea, can also be seen. On the other hand, there is a difference of opinion as to whether the great pyramids of Egypt can actually be seen.
………….
Contact address of the environmental department:[email protected]