What is the wisdom behind the creation of this enormous number of planets, and what is the purpose of their existence, if life is confined to planet Earth alone?

It is not permissible to interject texts from the Qur’an and Sunnah into natural sciences and the details of the universe's creation. The Qur’an neither denies nor affirms life on other planets, and the noble verses about stars and planets were revealed to demonstrate the greatness of Allah, not to detail information about the universe. Islamic Sharia cannot definitively assert the existence of life on other planets and galaxies, for Allah's creation is too vast for us to encompass. The wisdom behind the creation of stars is evident in their use as a means to infer the Creator's greatness and to ponder His signs, such as His saying, the Almighty: "that you may know the number of years and the reckoning." Everything Allah created in the heavens and the earth was created with truth and for truth, to be signs for the pious. Stars are "subjected" by Allah's command, and this magnificent creation carries wisdoms that human minds cannot comprehend. And Allah continues to create what we do not know.