An artificial satellite is a device that orbits a planet.
The concept of satellite , which comes from the Latin satelles , can be used to name two astronomical objects with very different characteristics.
It may be, on the one hand, a celestial body that is described as opaque, since it can only shine by reflecting the light that reaches it from the sun. These satellites have the peculiarity of rotating around a planet .
artificial satellites
It is possible to speak, on the other hand, of artificial satellites . In this case, these are devices that trace orbits around our planet or another, and whose objective is to transport equipment that allows the collection and retransmission of information .
It could be said that they are ships sent into space using a launch vehicle. Once they fulfill their function, they may remain in orbit and become space debris. At a general level, on the other hand, a satellite is a human being or something that is under the influence of another or that directly has a dependence on it.
Classification according to type
In the case of artificial satellites we can establish that there are several types of them depending on the missions or areas in which they work. In this way, for example, we can talk about the so-called communications satellites that are basically used to act as antennas in those areas that have little development or are very large.
In this sense, we should highlight Telstar 1 , which is the first of this type to be put into orbit, it did so in 1962 . It must also be emphasized that this type of satellites are used, among other things, to broadcast television signals.
Another type of artificial satellites are the so-called meteorological satellites which, as their name indicates, are used to know and study both the climate that exists on our planet and the atmospheric weather that exists on it. Thus, thanks to them you can glimpse the clouds, the pollution or even the evolution of the ozone layer that exists in Antarctica .
And to these two types of artificial satellites it is inevitable that we add a third. Specifically, we are referring to those known as spy satellites that are used primarily in the military field or in the intelligence sector. And these allow obtaining secret and very important information in communication and observation tasks such as the interception of signals in matters of attack.
The Moon is the only natural satellite of the Earth.
The Moon, a natural satellite
It is important to note that the Earth has only one natural satellite : the Moon , which has a diameter of 3,476 kilometers and is 384,400 kilometers away from our planet. The natural satellites of any planet, by extension, are often referred to as moons .
Although, in general, we talk about a primary planet (in this case, the Earth ) and the satellite that orbits around it (the Moon ), there are cases in which the planet and the satellite have similar masses. Specialists, given this, talk about binary systems . That happens with Pluto and the satellite called Charon .
The satellites of the Solar System can be classified as co-orbital satellites (if they move in the same orbit), asteroidal satellites (they are found around asteroids), shepherd satellites (they allow rings to be kept in their position) or Trojan satellites (a certain planet and a certain satellite also have other satellites at some Lagrange points ).