Question 453: Is there a planet other than the planet Earth where people exist, or any other kind to whom Prophets and Messengers and Muhammad sawas. and Imams a.s were sent?
Answer: In the Name of Allah the Merciful, the Most Merciful.
And all praise is due to Allah, Lord of the Worlds, and may Allah send His prayers upon Muhammad and the family of Muhammad, the Imams and Mahdis and send great greetings.
May Allah reward the best reward of the charitable ones, and may Allah help you in all that is good. There exist many types of creatures on other planets. And some of them we can see with our physical eyes [our material eyes], if they become present here between our hands, and some of them, we cannot see them because they go out of the density and color range of our eyesight. Also, some of these creatures are Mukallaf (assigned), and Allah SWT. send Messengers to them too in order that He may warn them, and give them glad tidings in exactly the same fashion as He has sent Messengers to human beings and jinn on this earth.
And may peace, mercy and blessings of Allah be upon you.
Al-Jawab Al-Munir (Enlightening Answers across the Ether) part 5, Imam Ahmed Alhasan (a.s)