A horoscope is a fine mixture of fortune-telling bullshit and verifiable astronomical facts. The latter have the form of "where the celestial bodies could be seen at the hour of the client's birth", or "does Jupiter currently appear to be moving forward or backward in the sky".

The average Visual Basic programmer and the world's best mathematician are going to be about equally good at writing the fortune-telling part, but the mathematician will have a much easier time getting the factual part right.

I don't think the kinds of people that believe astrology are actually verifying the astronomy though.