Human beings have long wondered: Are we alone in this vast universe? Do any other thinking beings exist on other worlds?
We have reason to wonder. Is our planet the only one to bear the fruit of life from among the countless planets of the universe? Is such an eventuality likely? In Allah's creation, does a tree with many branches bear only a single fruit?
A small insect that lives its whole life feeding from a single grape might not be aware that any other grapes exist. However, we are thinking beings, and we can contemplate something outside of our immediate experience. We know there are worlds around other stars, and even if it turns out that the conditions that allow for life are rare, we know for a fact that the Earth possesses these conditions. Allah's universe is truly vast, and around all those countless stars, would not the conditions found on Earth be repeated over and over again? Allah creates everything for a purpose. He who created us and gave us the ability to think is certainly capable of doing so elsewhere in the universe.
Scientists suspect that due to the vastness of space, there must be other intelligent life out there, other civilizations in the universe. They have, as a consequence, committed considerable resources to the search for extra-terrestrial intelligence (SETI). The SETI program employs powerful radio telescopes to detect the broadcasts of other intelligent beings who might exist but who would be forever separated from us by insurmountably vast distances and the limitation of the speed of light.
Some Muslims, though, have their reservations about these ideas. They ask: Where in the Qur'ân does it mention extra-terrestrial life? However, a better question would be: Does the Qur'ân say anything that relates to the topic one way or the other?
Consider the verse: "And We have honored the progeny of Adam and carried them on land and on sea, given them for sustenance things good and pure; and preferred them greatly over many of those whom We have created." [Sûrah al-Isrâ': 70]
We might ask - glancing at the sky when we do – where are those others whom Allah has preferred with special endowments? It would be wrong of us to jump ahead of ourselves and assert that the verse is speaking about extra-terrestrial beings living on other worlds. At the same time, we certainly have no reason to object to the possibility of extra-terrestrial life.
Now we must look at the verse: "And among His signs is the creation of the heavens and the earth, and the beasts that He has scattered throughout them both: and He has power to gather them together when He wills." [Sûrah al-Shûrâ: 29]
Allah's words: "throughout them both" (fîhimâ) cannot be interpreted except to mean that the living things mentioned in the verse exist both within the heavens and on Earth. The word we have translated as "beasts" is dâbbah, which can only refer to animate living organism that trod upon the land. The word can apply to animals or even to humans, but it always indicates living creatures that the ability to walk. It is not possible to interpret this word in any other way or claim that it refers in this verse to "angels".
Interpreting the "beasts" that exist in the heavens to refer to angels is shown to be an erroneous interpretation by another verse where Allah makes a clear distinction between the two: "Everything in the heavens and on Earth from among the beasts and the angels makes obeisance to Allah, and they are not haughty." [Sûrah al-Nahl: 49]
As for intelligent life, though there is no textual evidence that refers to it decisively, there is certainly enough evidence to allow for its possibility. In many verses, Allah uses the pronoun "who" (man) – which is used in Arabic to refer to rational beings – to refer to the denizens of the heavens and the Earth.
Allah says: "All who are in the heavens and on Earth make obeisance to Allah, willingly or unwillingly, as do their shadows in the morning and the evening." [Sûrah al-Ra`d: 15]
He says: " Unto Him belongs all who are in the heavens and on Earth. And those who dwell in His presence are not too proud to worship Him, nor do they weary." [Sûrah al-Anbiyâ': 19]
He also says: "All who are in the heavens and on Earth but come to the Beneficent as a servant. He takes account of them all, and has numbered them all precisely." [Sûrah Maryam: 93-94]
From the expressions of the Qur'ân, a Muslim should have no objection to the possibility of extra-terrestrial life and extra-terrestrial intelligence. There is no incompatibility between Islamic teachings and the idea of life existing on other worlds.
And Allah knows best.