Natural space satellites of the planets

There are 8 planets in the Solar System. They are conventionally divided into inner and outer. The inner ones are “inside” the Earth’s orbit, and the outer ones are beyond it. Mercury and Venus are considered inner planets. The inner planets do not have natural satellites.

The Earth has one natural satellite , the Moon. According to the mega-impact model, the Moon was formed as a result of the Earth’s collision with a large cosmic body 4.5 billion years ago. After the impact, a significant part of it broke off and was thrown into near-Earth orbit. The Moon is the only naturally formed satellite of planet Earth .

The planet Mars has two natural satellites . Their names are Phobos and Deimos. Long-term observations have shown that Phobos’s movement is gradually slowing down. This is due to the tidal influence of Mars. As a result, the satellite’s orbit is decreasing. In the future, Phobos will be destroyed by tidal forces when it approaches Mars.

Jupiter, Saturn, Uranus and Neptune are giant planets. Jupiter has quite a few satellites – about 70. The largest of them – Europa, Ganymede, Callisto, Io – were discovered by Galileo in the 17th century.

Saturn has the largest number of natural satellites in the Solar System – 82. Most of Saturn’s satellites are characterized by:

small size;
the presence of ice and rocks on surfaces;
high reflectivity.
Uranus is located at a great distance from Earth, so it is not easy to observe. In 1787, 2 satellites were first discovered – Titania and Oberon. More informative observations were made in 2013. Currently, 27 celestial bodies are known to revolve around Uranus and 14 to revolve around Neptune. According to scientists, not all natural satellites of the planets of the Solar System have been discovered.