What are natural satellites of a planet


This is what a Meteosat looks like. It's a certain type of satellite: it helps to predict the weather. This photo shows only one model on earth.

A satellite is a heavenly companion. Most of the time it refers to the companions who circle our earth high up in the sky. The moon is a natural satellite of the earth. The artificial satellites are much smaller: people shot them into space with rockets. The word satellite comes from the Latin language and means "companion".

Artificial satellites have been around since 1957. Since then, several hundred of them have been constantly moving around the earth. Many of them rotate directly with the earth and can therefore always be seen in the same place in the sky with a powerful telescope. Some observe the earth or space for us. Others are there to take TV shows, phone calls and other things from place to place.

What are natural satellites?

The earth has a natural satellite, the moon. It wasn't until the 17th century that humans discovered that other planets also have moons. This was made possible by the invention of the telescope. First the largest moons of Jupiter could be seen. Today we know that large planets like Jupiter and Saturn have dozens of moons. Most of them are very small and only a few are as big as our moon.

It is not known exactly how all moons were formed. Some may initially fly around the sun like planets: when they got close to a planet, they were attracted by its gravity. Since then, they have been revolving around the planet, which is called an orbit. Others arguably arose when two planets collided with each other.

What are artificial satellites?

A US space probe that observed the planet Mars: the Mars Observer, pronounced Opp-ssörwa.

In 1957, the Soviet Union launched the first artificial satellite into space with a rocket. The satellite in it was called Sputnik. It circled the earth for 92 days before falling down. A year later, Explorer was the US's first satellite. This country has now shot up most of the satellites. There are several hundred.

Such a satellite orbits the earth permanently, some fly several hundred kilometers, others several 10,000 kilometers. Some of them rotate with the earth in such a way that they seem to be above a certain point on the earth. You can observe the earth with satellites, for example to make maps. Other satellites receive message signals and send them on to another, distant location on earth. These signals consist, for example, of telephone calls or television broadcasts.

The International Space Station is also a satellite. Like some other satellites, they can even be seen from Earth at the right moment. In addition, there are many parts buzzing around the earth, like old rocket parts that have not fallen back to the earth. Some artificial satellites do not orbit the earth, but rather other planets or moons, such as Mars. They are called orbiter, from the English word "orbit" for orbit. If the satellite does not orbit a planet or moon, but flies through space, then it is a space probe.

  • Phobos is a moon of Mars

  • Replica of Venera 1, a space probe to Venus

  • In 1967, the Surveyor 3 probe landed on the moon. Astronauts took this photo there two years later.

  • Hubble space telescope, pronounced Habbl