A History of Earth Observation
Before there were satellites, there were pigeons…
What is Earth Observation?
“The single location where we can learn the most about our planet is found nowhere on Earth but high up above it.” – European Space Agency
Earth observation involves gathering information about the Earth’s surface using remote sensing. It allows us to obtain data from a vantage point we can’t necessarily reach ourselves, by sending something else to collect it for us. Today we think about it in terms of satellites orbiting the Earth, but this wasn’t always the case…
Earth observation began shortly after the invention of photography. In 1858, Gaspard Felix Tournachon (known as “Nadar”) captured the first recorded aerial photograph from a balloon. He quickly realised the potential his images could have, offering his services to the French military.
Inspired by balloon photography, in the late 1880s Arthur Batut pioneered the use of kites for the same feat. He managed to produce stunning aerial photographs by attaching timed cameras to kites. People at the time were not accustomed to seeing their towns from above, so his work received considerable media attention.
Perhaps more inventive still was Julius Neubranner, a photography enthusiast and pigeon fancier. In 1903, he patented the “breast mounted pigeon camera.” As the name suggests, the camera could be strapped to a carrier pigeon. It took automatic exposures every 30 seconds. While pigeons had the advantage of speed compared to balloons, and distance compared to kites, the birds couldn’t always be relied on to fly over the desired location.
With the invention of the airplane, aerial photography became common place. The next breakthrough came with the world’s first space rocket, the V-2. This was developed in Germany during the Second World War as a ballistic missile. When the war ended, V-2 technology was acquired by America. In 1946, a V-2 rocket, launched from White Sands New Mexico, was used to take the first image of the Earth from space.
The Space Age
The launch of Sputnik 1 in 1957, changed Earth observation forever. For the first time we had the ability to look back at our planet from orbit. Satellites that followed carried increasingly sophisticated instruments to observe the Earth, not only in visual light as the early photographers had done, but also in other wavelengths of the electromagnetic spectrum.
TIROS (Television Infrared Observation Satellite) was NASA’s first programme to test the viability of satellites for Earth observation, to help make decisions on the ground. For example, whether to evacuate an area due to an impending hurricane. The programme produced the first accurate weather forecasts based on satellite data, and in 1962 TIROS began providing continuous coverage of Earth’s weather.
In 1968, humans ventured beyond Earth’s orbit for the first time. Apollo 8 saw three astronauts travel around the Moon and return safely. On their journey, they captured one of the most iconic images of the Space Age. It showed the Earth rising above the lunar horizon. This new perspective of Earth as a single blue oasis in the black void of space, inspired a new sense of responsibility to protect the planet.
Earth Observation Today
Data from Earth observation satellites has enabled us to see how the Earth is changing as a result of human activity. According to the Union of Concerned Scientists (UCS), over 700 Earth observation satellites are in orbit in 2019. They are an important scientific tool with a wide range of applications in areas such as:
* Weather forecasting
* Wildlife conservation
* Resource management
* Natural disaster response
* Climate science
At the National Space Centre, we are lucky enough to have a flight spare of Meteosat-7 on display. This is a European weather satellite, used as part of the Tsunami Warning System for the Indian Ocean. Meteosat-7 was part of a series of satellites that monitored the weather across the entire planet. They have since been replaced by a second generation of Meteosats, and as our demand for data increases, a third generation is set to follow. In light of the climate crisis, looking down at Earth has never been more important.
About the Author: Hannah Baker is the Assistant Curator at the National Space Centre