i don't know! ask a scientist.
It means that if you are alined with a country and they are attacked by Another Country the alined country will help and support your military.
It is called an "alignment". A perfect alignment, all planets in one line, as is frequently shown in cartoons for example, has a probability of zero. That is to say, it is so unlikely that it may be considered impossible.
This is called an "eclipse". When other planets like Mercury or Venus pass directly between the Earth and the Sun, it doesn't cause an eclipse, because the shadow of Venus or Mercury is too small. Instead, we call this a "Transit".
we call huge planets huge planets
Inner planets are terrestrial planets outer are jovian planets
a person who studies planets is a planetologist.
The rocky planets
the inner planets are sometimes called Terrestrial Planets
A syzygy
You don't.
exoplanets
very carefully...