Astrology vs. astronomy
Question

                Are we allowed to read our star signs?
Praise be to Allah.
    Al-Bukhaari said in his Saheeh: 
    Qutaadah said: “Allaah created these stars for three purposes: to adorn the 
    heavens, to stone the devils and as signs by which to navigate. Whoever 
    seeks anything else in them is mistaken and does not benefit from them, and 
    he is wasting his time and effort in seeking something of which he has no 
    knowledge.” (Saheeh al-Bukhaari, Baab fi’l-Nujoom, 2/240) 

    The study of the stars is divided into two 
    kinds: 

    1-    
    Study of the 
    influence of the stars (astrology)

    2-    
    Study of the 
    positions and movements of the stars (astronomy) 

    Study of the influence of the stars 
    (astrology) is divided into three categories: 

    1 – The belief that these stars have a real 
    influence in the sense that they create events and evil. This is major shirk 
    (shirk akbar), because whoever claims that there is another creator 
    alongside Allaah is a mushrik in the sense of major shirk, for he is 
    regarding a created thing that is subjugated as a creator which subjugates. 

    2 – Making this a reason to claim to have 
    knowledge of the unseen, so from the movements and changes in the stars he 
    deduces that such and such will happen because such and such has happened to 
    such and such a star. For example, he may say that one person’s life will be 
    miserable because he was born under this star, and that another person’s 
    life will be happy because he was born under that star. This person is 
    taking knowledge of the stars as a means to claim that he has knowledge of 
    the unseen, and claiming to have knowledge of the unseen is kufr (disbelief) 
    which puts one beyond the pale of Islam, because Allaah says (interpretation 
    of the meaning): 

    “Say: None in the heavens and the earth 
    knows the Ghayb (Unseen) except Allaah”[al-Naml 27:65] 

    The grammatical structure used in the 
    original Arabic – starting with the negation laa (translated here as 
    “none”) followed by the word illa (“except”) – is one of the most 
    emphatic ways of expressing exclusivity. So if a person claims to know the 
    unseen, he is effectively disbelieving what the Qur’aan says. 

    3 – If he believes that the stars are the 
    cause of good or bad things happening, this is minor shirk (shirk asghar), 
    i.e., when something happens he attributes it to the stars (and only 
    attributes it to the stars after it has happened). The basic principle is 
    that whoever believes that one thing is the cause of another when Allaah has 
    not made it so, is overstepping the mark and not acknowledging Allaah as He 
    should be acknowledged, because the One Who makes things happen is Allaah 
    alone. For example, if a person seeks healing from a piece of string (tied 
    around his wrist), and says, “I believe that healing is in the hand of 
    Allaah and this string is simply the means,” we would say to him, “You have 
    saved yourself from major shirk but you have fallen into lesser shirk, 
    because Allaah has not made string a clear means of healing. By doing this 
    you have transgressed against His position of Controller and Sustainer, by 
    making something a means to something else when Allaah has not made it so.” 
    The same applies to one who regards the stars as the cause of rainfall when 
    this is not the case. The evidence for that is the hadeeth narrated by 
    al-Bukhaari (801) and Muslim (104) from Zayd ibn Khaalid al-Juhani who said: 
    “The Messenger of Allaah SAWs (peace and blessings of Allaah be upon him) 
    led us in praying Fajr at al-Hudaybiyah, following rainfall during the 
    night. When he had finished praying, he turned to the people and said, ‘Do 
    you know what your Lord has said?’ They said, ‘Allaah and His Messenger know 
    best.’ He said, ‘This morning one of My slaves became a believer in Me and 
    one became a disbeliever. As for the one who said, “We have been given rain 
    by virtue of Allaah and His mercy,” he is a believer in Me and a disbeliever 
    in the stars. But as for the one who said, “We have been given rain by such 
    and such a star,” he is a disbeliever in Me and a believer in the stars.’” 
    So the one who attributes rain to the stars is saying that the stars caused 
    the rain. 

    Study of the positions and movements of the 
    stars (astronomy) is divided into two categories: 

    1 – If their movements are used to define 
    things that serve a religious purpose, this is something that is necessary. 
    If that helps in the case of religious obligations, then learning it is 
    obligatory, such as using the stars to determine the direction of the qiblah 
    (direction of Makkah). 

    2 – If their movements are used to define 
    things that serve a worldly purpose, there is nothing wrong with that. This 
    is of two types: 

    (a) 
    Using the stars 
    to work out directions, such as knowing that the pole lies to the north, and 
    that the Pole Star, which is close to it, revolves around the North Pole. 
    This is permissible. Allaah says (interpretation of the meaning):

    “And landmarks (signposts, during the 
    day) and by the stars (during the night), they (mankind) guide themselves”

    [al-Nahl 16:16]

    (b) 
    Using the stars to 
    work out the seasons, through learning the phases of the moon. Some of the 
    salaf regarded this as makrooh while others permitted it. The correct view 
    is that it is permissible and there is nothing makrooh in it, because there 
    is no shirk involved in it, unless one learns it in order to attribute 
    rainfall or cold weather to it, and says that this is what is causing that. 
    That is a kind of shirk. But simply knowing the time of year from it, 
    whether it is spring or autumn or winter, there is nothing wrong with that. 

    See al-Qawl al-Mufeed by Shaykh 
    Muhammad ibn ‘Uthaymeen (may Allaah have mercy on him), 2/102.