I learned about inner and outer planets in class. That outer planets have more moons and gas layers than inner planets was mentioned in the lesson, but not the reason why. When I asked my teacher about this, he said he didn’t want to go into more detail.
Answer
The difference between inner and outer planets – why one is boulder and the other has a lot of gas – was discussed earlier in
http://www.ikhebeenvraag.be/nischer/vragen3.jsp?id=19044
You will find something in question about the origin of the moon
http://www.ikhebeenvragen.be/nischer/vragen3.jsp?id=12169
The question then is why the outer planets have so many more moons. It has mainly to do with the fact that those gas planets have more mass, and so at the beginning of the history of the solar system could also keep a disk of gas and dust in which a kind of planetary system in miniature has arisen. In this sense, the existence of our moon is an anomaly, explained by a collision scenario. Mercury and Venus have no natural satellites at all, Mars has two, probably captured objects from the neighboring belt of minor planets.
Allow me to add one more thing. The fact that geography teachers do not know everything about astronomy has to do with the anomaly that astronomy in secondary education is introduced via geography, but that at university astronomy falls under physics and/or mathematics. You can become a very good geographer without having learned much about astronomy.
Answered by
Prof. dr. Christopher Waelkens
Astronomy
Old Market 13 3000 Leuven
https://www.kuleuven.be/
.