Astrology is called Pseudoscience.
For example: Let’s take Solar eclipse and see what Astrology and Astronomy say about the same.
Solar eclipse :
Scientific explanation: A solar eclipse occurs when the moon gets between Earth and the sun, and the moon casts a shadow over Earth
Astrology’s take on Solar eclipse :
Let’s take Hindu astrology for example :
The Hindu mythology says Solar eclipse is caused by Asura Svarbhanu (Snake) who pierced the sun (according to rigveda)
According to Puranas (the post Vedic texts) : Svarbhanu disguised himself as a Deva to drink the Amrita (nectar of immortality). So, Lord Vishnu who was in his Mohini form beheaded the demon Svarbhanu - now he was split into two entities: Rahu and Ketu.
Rahu - the head of the snake or dragon , Ketu - the tail of the dragon. The head which is Rahu is in eternal cosmic journey around the Sun(he is chasing the Sun) and sometimes catches and swallows Sun and moon causing Solar and Lunar eclipses.
Rahu and Ketu are called the Lunar nodes.
Basically, Lunar node is the point at which the Moon, Sun and Earth are in the same plane.
Rahu causing a Solar eclipse:
In western Astrology this is called Caput Draconis and Cauda Draconis :
credit : Google images
Rahu (the ascending node ) is called the Head of the Dragon and Ketu (the descending node ) is called tail of the Dragon.
9 Heavenly bodies of Indian Astrology :
Hindu astrology considers : the following as Nava Graha (nine heavenly bodies )
Sun, Moon, Mercury, Mar, Venus, Jupiter, Saturn, Rahu and Ketu ( Same as in Greek astrology)
Rahu and Ketu are considered as Shadow planets.
90 minutes of a day is allocated to Rahu and this time is considered as inauspicious time, it’s called Rahu Kaal.
People in India especially in the south, strictly observe the practice of avoiding starting any new work in Rahu Kaal.
Looks like ancients were trying to figure out things, with the limited technology they had and were successful to an extent in predicting solar and lunar eclipses using Lunar nodes as references.
But, they didn’t actually know what caused the eclipses. This is why it’s called Pseudoscience.
Pseudoscience is a set of beliefs which claim to be scientific, but it lacks the method or fails to explain a phenomena as accurately as Real science.