Satellites are spacecraft which orbit around the Earth. They have a variety of functions, yet all of them are useful because of their height. As an example, weather satellites look over our atmosphere. Amazingly, there are about 1000 satellites operating right now! These range from GPS devices to entire space stations (yes, the ISS is a satellite).
Difference Between Natural and Artifical Satellites
Before we look at what satellites do, we need to clarify what they are. The term ‘satellite’ actually has multiple meanings in astronomy. The ones we’re talking about here are man-made objects. We call these artificial satellites. This makes sense: floating heaps of metal are by no means natural. Oppositely, the other type of satellites in astronomy are natural satellites. Natural satellites are things like moons and rings. These are held in place by a planet’s gravity and so are stuck in its orbit. We didn’t put them there.
The Earth’s Moon is a natural satellite.
This is a small distinction, but clearly an important one. There’s a reason we landed on the Moon and not a weather satellite! That being said, let’s look at what makes artificial satellites so important.
Applications of Satellites
Whether or not we realize it, satellites are essential to our daily lives. We use satellites when we check the weather, use a digital map, and (for some people) when we use the internet. Though far away, they have a very direct impact on our livelihood. Let’s dig into the uses of satellites.
Have you ever seen a satellite dish on someone’s house (even your own)? These devices receive signals from satellites all the way out in space! This way, they can become connected to a variety of networks including the Internet. Communications satellites also commonly used to let people watch television.
A satellite dish. Sadly, you can’t substitute a plate.
Nowadays, there are tons of pictures of storms in Earth’s atmosphere. These are both beautiful and very useful. But how in the world could we take them? The answer is: with imaging satellites. Imaging satellites are satellites equipped with cameras. They allow us to see more of our planet. Even better, they allow us to map out other worlds, too. The Hubble Space Telescope is an imaging satellite. Resting over the Earth’s atmosphere, this telescope studies distant galaxies. Because it’s in outer space, it can get much clearer pictures than it could from the ground.
One of the more common uses for satellites is to monitor the Earth’s weather. Weather satellites generally study clouds, tracking both their size and temperature. This helps us to predict when storms might occur. It’s also important for tracking the movement of hurricanes. Knowing where they’re at, we can get people to evacuate dangerous areas.
The most practical application of satellites is GPS. GPS – the Global Positioning Service – is a system of satellites owned by the US government. Its goal is to track the location of devices (like phones) on Earth. Because of this system, it’s relatively easy for us to find our way around. Applications like Google Maps use GPS.
Perhaps the most important satellite of them all is the International Space Station (ISS). It’s a spacecraft with a crew of about 6 to 7 people. Interestingly, the ISS orbits the Earth about 15 times per day.
And what does it do, flying around our Earth all day? For the most part, research. The ISS serves as a place where we can test how things work in space. It’s one of the few zero-gravity laboratories. So, it helps us learn more about what living out in space is like.