Almost 3,000 operational spaceships orbit our earth. That number is growing steadily thanks to cheaper materials and smaller satellites.
With so many satellites in orbit, it can create problems including space debris and the way they change our view of the night sky. However, satellites provide an important service.
Many people are familiar with GPS, which helps us navigate. Some may know that satellites provide important data for our weather forecasts. But satellites affect our lives in many ways – and some of them may surprise you.
1. Spend money
Whether you’re paying for your morning coffee with contactless payments, Google Pay, or even cash withdrawn from an ATM, nothing would be possible without satellites. In fact, all financial transactions – from multi-million pound stock market transactions to your monthly Netflix subscription – rely on satellite location and timing services for security reasons.
Global navigation satellite systems orbit about 20,000 km above the surface of the earth and continuously communicate with phones and computers to tell them exactly where they are and what time it is. GPS, a US system, is the best known of these, but the European Galileo system and the Russian GLONASS system offer similar services.
We rely on this precise point in time to ensure financial transactions are synchronized. If we got our timing wrong, money could get into one person’s account before it leaves the other person. This is especially problematic for stock market trading, where prices can fluctuate dramatically in a matter of seconds, but it is also a security requirement for financial institutions worldwide.
2. Save lives
Many people will have heard that natural disasters such as forest fires and tropical storms are becoming more frequent and devastating due to climate change. Fortunately, satellites provide a way to monitor these disasters, study their behavior, and even aid our response and relief efforts.
German company OroraTech uses data from a number of spacecraft to detect outbreaks of fire as soon as they occur. They use infrared images to identify hot spots, wind readings to predict the path of the fire, and terrain and vegetation maps to help fire fighters plan their response.
Data from satellites has also been used to monitor tropical storms, predict their path, and help communities prepare for the expected impact.
While all of these efforts are admirable, for such a drastic global challenge we need a coordinated global response. In 2000, 17 countries agreed to freely share satellite data in emergencies. To date, this charter has been used in disaster support in nearly 700 countries using data from more than 60 satellites.
3. Stand up for what is right
Satellites operate in a “no man’s land” where no country or entity can claim any region of space as its own. Because of this, unlike airplanes or drones, which may need permission to enter another country’s airspace, satellites can capture images anywhere on earth.
Most satellites operate near Earth, only 300 km to 1000 km above our heads, and only take 90 minutes to complete a full orbit around the Earth. As the earth rotates beneath the spaceship, each orbit brings new areas of the earth into view.
With nearly 3,000 satellites overhead, it’s very difficult to hide in the sky from all eyes. Because of this, satellite data has become an important source for activists, journalists and investigators. It has empowered local communities to tackle illegal deforestation, enabled the prosecution of war criminals, and exposed government fabrications like the downing of Malaysia Airlines MH17.
4. Stop pirates
All ships of a certain size must broadcast their position about every minute. Near the coast these signals can be picked up by antennas on land. However, when ships are at sea, these signals can only be received by satellites and of course by other nearby ships.
Pirates, illegal fishermen and others who do no good often do not carry a beacon or turn it off to avoid being detected. Fortunately, high resolution satellite imagery can detect boats against the dark surrounding ocean using a technique known as synthetic aperture radar.
By comparing the locations of the ships seen to the location of the beacons that were detected, we can identify the ships that have “gone dark” and alert the authorities that something suspicious is afoot.
5. Discover endangered species
As you might imagine, animal counting is a tough business made even more difficult by animals living in remote, hard-to-reach places. To address this challenge, satellite imagery was used to estimate the size of penguin colonies by measuring the amount of guano (bird droppings) on the ice.
Recently, scientists have even been able to identify and count individual animals such as whales and elephants in images from space using extremely high-resolution satellite data. Far from tracking down a lost dog, it is an incredible tool for conservationists trying to save endangered species from extinction through poaching, human encroachment, and habitat destruction.
6. In search of life
Not all satellites orbiting our Earth are looking down – some of them are looking out into space. There are many telescopes on earth that we can use to examine our skies. However, if we put these telescopes into orbit, we can avoid looking through Earth’s atmosphere for a clearer view of the cosmos beyond.
This clear view is especially important in our search for exoplanets – planets orbiting other stars outside of our solar system. In contrast to stars, planets do not emit their own source of light. Hence, we recognize them by measuring the tiny drop in starlight that occurs as the planet passes in front of the star it is orbiting.
The hope is that some of these planets can be like our own earth and harbor extraterrestrial life. Cheops, a European Space Agency mission launched in 2019, has just started sending back information about their first discovered distant worlds. It may seem like a long shot, but one day these missions could answer the age-old question of whether anyone is out there.
This article by Ciara McGrath, Research Associate, Electronics and Electrical Engineering at the University of Strathclyde, has been republished by The Conversation under a Creative Commons license. Read the original article.
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