When one first considers this subject, it does sound illogical and impossible.
It really does seem highly unlikely that any heavenly body should have any effect on us, at all, doesn't it?
And yet ...
Sunny days make us feel healthier and happier, and some people seem to change their personalities at the time of the full moon, so perhaps there could be something in it.
After all, the moon has a huge effect on the sea's tides ~ ie. the water on the Earth ~ and we humans / animals are made up mostly of water, so isn't it likely, or at least possible, that the moon should also have an effect on us?
Maybe the other planets do, too. They all inter-react, re gravity etc. Maybe their gravitational pulls affect us? Perhaps?
So, perhaps there are some 'truths' in astrology, but is it really possibly that stars, so very far away, might also affect us? ~ I doubt it.
But they have already had a very important effect on us.
We are made of stardust!