How Satellites Have Played a Role in Protection of Earth

Introduction

For thousands of years, human beings could only wonder about Earth and the other observable planets in the solar system. Many ideas—for example, that the Earth was a sphere and that it traveled around the sun—were based on brilliant reasoning. However, it was only with the development of rockets that could send satellites to space that brought about space exploration. Artificial satellites are any object purposely placed into orbit around Earth, other planets, or the sun. Earth-orbiting satellites can provide data to map Earth, determine the size and shape of the Earth, and detect rises in ocean levels. Russian scientists and engineers shook the world by placing into orbit the first man-made satellite, Sputnik 1, which was launched on October 4, 1957. Named after the Russian word for “traveling companion of the world” (sputnik zemli), it was a small satellite, measuring 58cm (0.58m) across. It circled the Earth once every 96.2 minutes and spent 92 days in orbit, completing a total of 1,400 orbits. No sooner had the world recovered from the excitement of this first achievement than it was again shaken by the launching of Sputnik 2 on November 3, 1957. Sputnik 2 weighed 508.5kg and carried a husky dog named Laika.

The Role of Satellites in Earth's Protection

Since the early launching of the first artificial satellite, thousands of these “man-made moons” have been rocketed into Earth’s orbit. Today, artificial satellites play key roles in the communications industry, military intelligence, and the scientific study of both Earth and outer space. Different types of artificial satellites have been successfully placed in orbit. These include weather satellites, navigation satellites, communication satellites, and astronomical satellites. Advances made in radio, telemetering, and television made it possible to guide unmanned satellites into orbit. This also enabled the transmission of all kinds of scientific data and pictures to ground stations. Environmental satellites circle the Earth in an orbit that passes over the north and south poles several times a day. Pictorial information about the Earth’s atmosphere and ocean is relayed back to the surface, where it is used to monitor changes in the environment. The information that scientists gather from space missions such as these helps increase their understanding of the planet in which they live, Earth. They can apply this knowledge to better understand the forces that created the Earth and continue to act upon it (Morgan, 2009).

The Impact of Satellite Technology

People had not known for so many years what the Earth looked like from space until the late 1960s, when they saw for the first time a photograph of the Earth from space taken by the Apollo mission crew on the mission to the moon. Engineers today have developed different types of satellites, each designed to serve a specific purpose or mission. Some satellites were built specifically for discovery and research, which were mostly launched by the National Aeronautics and Space Administration (NASA) in what was called the mission to the first satellite in an international program. The satellite was placed into orbit with one of its major missions being to understand the impact of human activities on the global environment. Another of such missions was the Earth Resources Technology Satellite (ERTS), which was first launched in 1972. It continues to acquire periodic multi-spectral images of the Earth’s surface to support investigations in areas such as agriculture, forestry, and land, mineral, and mineral resources (NASA, 2023).

Satellites and Environmental Awareness

Satellites have done far more for Earth and its inhabitants than just inspire us with pretty images of the Earth. It is very important to the future of life on our planet to understand how what we do affects the delicate balance of the environment. Using information from satellites, we are beginning to know how pollution from our various human activities affects the environment. You are probably familiar with the use of satellites for transmitting TV signals and telephone calls, but you may not be as familiar with how much satellites have helped us to understand and take care of our planet. Satellites have studied oceans, the atmosphere, clouds, weather, rainforests, deserts, cities, farmlands, ice sheets, and just about everything else on and even in Earth. Satellites have shown that the ozone is disappearing over some parts of Earth, which resulted from the release of harmful chemicals into the atmosphere produced by humans and their activities. Therefore, we know that we must find and use chemicals that are less damaging to our atmosphere.

(“The ozone hole over the South Pole is apparent in this false-color image taken by a satellite in October 1999. Low levels of ozone are shown in blue. Ozone is a gas that blocks harmful ultraviolet sunlight. Industrial chemicals released into the atmosphere have caused ozone to break down, opening holes in the ozone layer that tend to concentrate at the poles.” – Anonymous, from Encarta Encyclopedia 2009).

Weather Prediction and Natural Disasters

We use satellites to predict the weather. We may not be able to change the weather, but having an idea ahead of time about what it’s likely to do gives us the chance to prepare. The two GOES satellites, stationed high above the east and west coasts of the United States, let us track hurricanes and other storms as they develop. Having this view from space gives people enough warning of dangerous weather to prepare and even evacuate vulnerable areas where a hurricane might hit. Two satellites, TOPEX/Poseidon and Jason-1, have been studying the oceans. They have helped us to understand the complex movement of ocean water and to make long-term weather predictions. The oceans have a great effect on weather because they store a lot of heat. These satellites have observed the event known as El Niño, in which unusually warm water collects in the Pacific Ocean near South America, causing very heavy rain in some parts of the world and drought in others (NOAA, 2023).

Monitoring Remote Regions

Some remote parts of our planet are almost impossible to keep an eye on except from space. Frequent satellite images of a rainforest in South America can show how fast this precious habitat is shrinking. Views from space of the North and South poles allow us to monitor the shrinking of ice sheets—important indicators of global warming and possible flooding of coastal regions. Satellites that study Earth are not just fancy cameras in space. Many of them have special instruments that measure light that our eyes cannot see and can reveal important information such as the height of all the oceans all over the Earth, or the wind speed inside clouds. Our home planet, the Earth, is the focus of a lot of NASA missions. In the International Solar-Terrestrial Physics (ISTP) initiative, a number of spacecraft were launched to study the influence of the sun on Earth’s environment. The planet itself is the target for Mission to Planet Earth (MTPE), a long-term program for comprehensive studies. Earth-orbiting satellites will monitor Earth’s atmosphere, landmass, oceans, and ice sheets to document the complex processes and interactions taking place (NASA, 2023).

Conclusion

In the second half of the 20th century, more advances in the study of Earth and its components occurred due to the development of rockets that could send and observe Earth from space with satellites equipped with scientific instruments. Astronauts landed on the moon and gathered ancient rocks that revealed much about the early solar system. During this remarkable advancement in human history, humans also sent unmanned spacecraft to explore the other planets in the solar system. The information relayed by these satellites provided new insights about Earth and has helped develop new theories about how the Earth was formed. From the information given by Earth-orbiting satellites, we now know that the Earth is one of the most geologically active of all the planets and moons in the solar system. Earth is constantly changing over long periods of time; land is built up and worn away, oceans are formed and reformed, and continents move around, break-up, and merge. Life itself contributes to changes on Earth, especially in the way living things can alter Earth’s atmosphere. Today, scientists are working towards placing into orbit faster and safer satellites, which will last longer in orbit. Advances made in satellite manufacturing and a variety of scientific fields have broadened our knowledge about Earth. In conclusion, by studying Earth’s atmosphere, its surface, and its interior, scientists have learned much about how Earth came into existence, how it changed, and why it continues to change (Morgan, 2009).

References

• Morgan, J. (2009). Earth and Space Science. Encarta Encyclopedia.
• NASA. (2023). Missions to Planet Earth. National Aeronautics and Space Administration.
• NOAA. (2023). El Niño & La Niña: Frequently Asked Questions. National Oceanic and Atmospheric Administration.