i got this from http://www.islamanswers.net/miracles/moon.htm
Did The Prophet Muhammad split the moon as a miracle?
In the name of God, the Merciful, the Compassionate
The Hour has approached, and the moon split. But whenever they see a sign, they turn away and say, ‘This is evident magic.’ (54:1-2)
The miracle of the splitting of the moon was demonstrated before a certain gathering who persisted in denial of Muhammad’s Prophethood. As was related by ‘Adbullah ibn Mas‘ud, while they were in Mina’ one night, the Prophet split the moon into two by a gesture of his index finger. The halves of the moon appeared one behind the mountain and the other in front of it. Then, the Prophet turned to us and said: ‘Be witnesses!’1
The Qur’an refers to this miracle in the following verses:
The Hour has approached, and the moon split. But whenever they see a sign, they turn away and say, ‘This is evident magic’. (al-Qamar, 54.1-2)
Materialist philosophers and their unreasoning imitators, who want to cast a shadow with their vicious delusions over such a bright miracle of the Prophet Muhammad, upon him be peace and blessings, as the splitting of the moon, say: ‘If the splitting of the moon had taken place, it would have been known to the whole world and related in all subsequent books of human history’.
Answer: The splitting of the moon was demonstrated before a certain gathering who contradicted the Prophet Muhammad, upon him be peace and blessings, in his cause as an evidence of his Prophethood. It happened momentarily at a time of night. Also, there were obstacles which prevented the others from seeing it, such as mist, clouds and time-differences between different parts of the world. Besides, at that time science and civilization were not yet well advanced and not widespread, and, therefore, the observation of the sky was very limited. Last but not least, there was nothing to necessitate that it should have been seen all over the world. It is because of these reasons that the splitting of the moon was not witnessed in the whole world and related in the history books of other nations.
In order to remove such clouds of delusions concerning the miracle of the splitting of the moon, heed the following Five Points:
The extreme stubborness of the unbelievers in the Hijaz at that time is well-known and is recorded in history. When the Qur’an, however, announced this incident to the whole world through its verse, The moon split, not any of those unbelievers, who denied the Qur’an, dared to contradict it in this announcement. If this incident had not occurred before their eyes, they would certainly have taken this verse as a pretext to attack the Prophet more formidably in his cause. However, neither the biographies of the Prophet, nor the books of history report anything to suggest that they denied the occurrence of this incident. What was reported concerning their reaction is as the verse records: They say, ‘This is evident magic’. The unbelievers declared the event to be magic, and they added further that if the caravans in other places had seen it, it truly happened, otherwise the Prophet bewitched them. When, however, the caravans coming the following morning from the Yemen and other places announced that they had witnessed the event, the unbelievers showed their usual reaction, saying,–God forbid!–‘The magic of Abu Talib’s orphan has affected even the heavens!’
The majority of the foremost scholars of meticulous research such as Sa’d al-Din al-Taftazani concluded that like the flowing of water from the fingers of the Prophet, upon him be peace, and his satisfying the thirst of a whole army with that water, and the grieving of the dry wooden pole–against which the Prophet used to lean while delivering sermons–because of its separation from him, and its being heard by a whole congregation, the splitting of the moon, too, is mutawatir, that is, it has been transmitted by one truthful group at each period to another, forming such a vast community that their agreement on a lie is inconceivable. It is as certain as a famous comet–named Haley–having appeared a thousand years ago, or as the existence of an island which we have not seen but exists. Therefore, it is unreasonable to foster baseless doubts about such certain, witnessed matters. In fact, it is sufficient for their acceptability that they are not impossible. As for the splitting of the moon, it is quite as possible as a mountain’s being split by a volcanic eruption.
Prophets work miracles to prove their claim of Prophethood and to convince deniers, not to compel belief. Therefore, every miracle had to be, and was, manifested to convince those who heard the claim of Prophethood. So, if they had been demonstrated in a way that could be seen by the whole world or would compel everyone to believe, this would have been contrary both to the wisdom of the All-Wise and the Divine purpose for creating man with free will, and sending religion, which entails that the ground be prepared for the mind’s acceptance without the power of choice being annulled. If, then, the All-Wise Creator had, because materialist philosophers fancy it so, left the moon split for one or two hours in order that it would be seen by the whole world and recorded in all books of human history, then it would have been no more than other astronomical events, without having been special to the Messengership of Muhammad, upon him be peace and blessings, and an evidence of his Prophethood. Or, it would have been such an obvious miracle that everyone would have felt compelled to believe for there would have been left for the will no way but to accept belief in him. This, in turn, would have resulted in that someone with a coal-like spirit like Abu Jahl would have remained at the same level as someone with a diamond-like spirit like Abu Bakr the Truthful, which means that the purpose of the creation of man with a special function and responsibility and the purpose of sending revelation would have been negated. That is why the miracle of the splitting of the moon was not shown to the whole world to be recorded in all books of human history.
Some unreasoning opponents argue that if that incident had taken place, in would have been mentioned in the histories of such nations as the Chinese, the Japanese and Americans. How could they have witnessed it, given that, when this event happened, in addition to other obstacles, it was barely sunset in such European countries as Spain, France and England, which were then enveloped in mists of ignorance, daytime in America and morning in China and Japan. A thousand curses on such toadies and sycophants of Europe!
(In some books there is an additional record that the moon fell to earth after it split into two parts. This was rejected by veracious scholars on account of its being added by a hypocrite who intended to reduce to nothing the value of this evident miracle.)
The splitting of the moon is not an ordinary incident which happened either due to particular causes or randoming so that it should be criticized from the viewpoint of the law of cause and effect. Rather, the All-Wise Creator of the sun and the moon made it happen as an extraordinary event in order to confirm the Prophethood of His Messenger and to support him in his claim. Therefore, it was shown as a convincing proof to certain people specified by Divine Wisdom because, as stated above, the nature of Divine guidance and human responsibility, and the purpose for raising a Messenger required it to be so. If it had not been concealed from the eyes of those who were not intended to see it and who had not yet heard the Prophethood of Muhammad due to some obstacles such as fog, clouds and time-differences, and if had occurred according to the law of cause and effect, then it would have been an ordinary astrological event, not a miracle peculiar to and connected with the Messengership of Muhammad, upon him be peace and blessings.
In conclusion, these arguments must be enough for any mind to be convinced of the possibility that the splitting of the moon occurred; now out of many evidences of its occurrence, we shall mention only six which have the strength of a six-fold consensus:
• The Companions of the Prophet, who were all men of justice and truthfulness, concurred upon its occurrence.
• All of the exacting interpreters of the Qur’an have agreed that the verse, The moon split indicates to the splitting of the moon with a gesture of Muhammad’s fingers, upon him be peace and blessings.
• All the truthful Traditionists narrated this incident through various authentic channels of transmission.
• All the men of truth and sainthood, men of inspiration and spiritual discovery have borne testimony to the occurrence of this incident.
• All the foremost theologians whose way differ greatly from each other and all the learned scholars have nevertheless agreed in their confirmation of this event.
• The Community of Muhammad, upon him be peace and blessings, who, as established by an authentic Prophetic tradition, never agree on an error, have accepted on its occurrence.
These six evidences are as clear as the sun to prove the splitting of the moon.
Conclusion: What we have put forward hitherto on this matter has been to establish the splitting of the moon by way of refuting the objections to the possibility of it. In a few concluding sentences we will now speak in the name of the truth and for the sake of belief. Now it is the turn of the truth to speak:
The Seal of the Prophets, upon him be peace and blessings, who is the luminous moon of the heaven of Messengership, proved his sainthood through his Ascension, which is the greatest miracle of his sainthood achieved through the quality of his worship–so elevated as to make him the beloved of God. In other words, by making Muhammad, an earthly being, travel through the heavens, God showed to the dwellers of the heavens and of the highest realms his superiority to them and his being His beloved. Similarly, through the splitting of the moon, which is set in the sky and bound to the earth, upon the gesture of the same earthly being, another great miracle was demonstrated for the inhabitants of the earth as an evidence of the Messengership of that earthly being. Thus, the Prophet Muhammad, upon him be peace and blessings, flew to the summit of perfections on the two brilliant wings of Messengership and sainthood–like the two bright halves of the moon split into two; he ascended so near as to the distance of two bowstrings–that is, to the highest rank, the nearest station to God–and so became the cause of pride of both the beings of the heavens and the inhabitants of the earth.
Upon him and upon his family be blessings and peace such as to fill the earth and heavens.
Glory be unto You! We have no knowledge save that which You have taught us; indeed, Your are the All-Knowing, All-Wise.
1. Bukhari, Manaqib, 27; Muslim, Kitab Sifat al-Munafiqin wa ahkamihim, 44.