- What is an artificial satellite?
- Types of artificial satellites
- What are artificial satellites for?
- How do artificial satellites work?
- Earth's artificial satellites
- Natural satellites
We explain what artificial satellites are, what they are for, how they work and what types exist. Also, natural satellites.
What is an artificial satellite?
In astronomy, satellites are the objects that they orbit to the planets. These can be natural satellites, composed of rocks, minerals and other elements, such as our Moon; or they can be artificial satellites, that is, man-made machines that orbit the planet Earth.
Artificial satellites are an important part of our lives, allowing us various daily and scientific tasks. For example, they fulfill various telecommunications functions. On the other hand, fragments of the same that constitute the so-called “space junk”.
The first to be put into orbit was Sputnik 1, thrown into the atmosphere by the former Soviet Union in 1957. This is how the so-called "Space Race" was formally inaugurated, an extension of the Cold War (1947-1991) between the United States and the USSR in the astronomical scientific field.
The first satellite was followed by Sputnik 2 and 3. In the second, the first living being in orbit the planet (and in dying in orbit, since no plans were made for his return): a Russian street dog named Laika. Since then, many countries have put hundreds of artificial satellites into orbit.
Artificial satellites have a useful life, after which they cease to function.In some cases they remain in orbit, gradually deteriorating until they become space junk, part of the metallic fragments that surround our planet. In other cases they succumb to gravity and disintegrate in the rub against the atmosphere.
Types of artificial satellites
Broadly speaking, artificial satellites are classified into two:
- Satellites observation. For astronomical or geolocation tasks,
- Telecommunications satellites.
However, according to its specific function, several subtypes can be distinguished:
- Satellites communications. Employees in telephony, radio, TV, etc.
- Meteorological satellites. In constant observation of the weather, atmospheric conditions and other important non-military mapping details.
- Navigation satellites. Necessary for geolocation and GPS.
- Reconnaissance satellites. Also called spy satellites, they are used for military or intelligence purposes.
- Astronomical satellites. They serve as orbiting telescopes to observe regions of outer space without intrusion from the atmosphere.
- Space stations. Structures of greater size and complexity than simple satellites, which allow life in space to Humans and drive there scientific experiments.
What are artificial satellites for?
Satellites allow phenomena such as hurricanes to be observed more globally.
Earlier we talked about the specific functions of satellites, that is, the tasks to which they can dedicate their resources. However, the essential function of satellites can be explained by the interest of human beings to have a better point of view of our planet and outer space, than from the I usually.
This allows not only a more global perspective of the planet, which is key in a world of economy and globalized interests, but also to be able to overcome the distortions inherent to the Earth's atmosphere and take a look outside.
On the other hand, satellites have been thought of as artifacts of war since its inception, since they could be equipped with extra-atmospheric weapons that allow them to attack rivals from unattainable positions on the border with space.
Likewise, thinking of less destructive purposes, the design and construction of solar energy capturing satellites have been proposed, which could serve as gigantic solar panels in space and supply Energy constant and almost gratuitous to Earth.
How do artificial satellites work?
Artificial satellites must be put into orbit by some kind of space launch, which once the desired region of the atmosphere is reached, leaves the artifact forever. Although there are hundreds of possible orbits, generally the satellites are located in three types of trajectories:
- Low Earth orbit (Low Earth Orbit). Between 700 and 1400 km high, with an orbital period of 80 to 150 minutes.
- Mean Earth orbit (Medium Earth Orbit). Between 9000 and 20,000 km of altitude, with an orbital period of 10 to 14 hours.
- Earth's high orbit (High Earth Orbit). At a height of 37,786 km above the Earth's equator, with a 24-hour orbital period over the same place on the planet.
Once in orbit, the satellites deploy their solar panels, which allows them to capture solar energy to send and receive information and instructions from Earth, using microwave antennas for the latter.
Earth's artificial satellites
At present, our planet is being orbited by more than 5,600 artificial satellites of different nature, as well as by 21,000 satellite fragments of more than 10 centimeters, some 500,000 of around one centimeter and more than one billion of particles in size to one centimeter.
All of the latter make up the so-called "space junk" and represent a real danger for future space missions and future satellites. This space junk ranges from astronaut gloves to broken telescopes and fragments of disused spacecraft, nuts, bolts, fragments of matter, etc.
Through the website http://stuffin.space all satellites and space debris on the planet can be observed in real time.
Natural satellites
Unlike artificial satellites, natural satellites were born together with the astronomical body they orbit (generally planets) or became trapped in their orbit as a result of some type of cosmic or astronomical phenomenon.
The most obvious case of natural satellites is our Moon, but there are many more on other planets in the world. Solar system. Some are similar in size and shape to ours, and others consist of rocks of various shapes or sets of asteroids that make up "rings" around the planet, as happens with Saturn.