Do aliens exist? If so, does that refute the existance of God?

Just watched Part 1 of the documentary, "Into the Universe with Stephen Hawking" which talks about Aliens and found it to be fascinating. There were some new ideas I learned and other ideas that were confirmed to me. For instance, I knew that Hawking strongly believes that alien life has to exist, just based on the sheer size of the universe. In fact, he believes it would be unlikely for alien life NOT to exist. What I didn't know was that alien life could exist within our own solar system, for example on Mars or more interestingly, on the moon Europa circling Jupiter. With regards to Eurupa, this moon is covered by a layer of ice 15 miles thick. However, because of its egg-shaped orbit around Jupiter, it expands and contracts, releasing lots energy, leading scientists to hypothesize that liquid water may exist underneath the ice surface. A quick look at Wikipedia reveals that though space missions to this moon have been suggested, it would be extremely expensive to put something together. I think it would be remarkable if we could send an unmanned device to this moon. Just the mission itself would inspire a generation.

Second thing I learned was that water isn't essential to life. Life could exist in other a soup of others chemicals too, such as liquid nitrogen or even mixtures of gases. Life could even exist without light, which it certainly does in the deepest parts of Earths oceans. Some planets are only gaseous, while others are too cold to support liquid water, but might be able to support liquid nitrogen. The point is, the possibilities are endless, and almost every shape and form of life must exist somewhere.

Hawking is also skeptical of supposed "encounters" with aliens that are occasionally reported on earth. To him, it makes no sense for aliens to take the time to travel across the galaxy only to arrive on earth unannounced and secretly find lonely and abduct them. Hawking fears that if aliens do come to earth, it won't be for peaceful purposes.

It was an interesting documentary and certainly fun to watch. After it was over, I was wondering if the existence of aliens would refute or confirm the existence of God to believers on Earth.

This question has almost certainly has been posed to religious scholars. Do any of my readers know the answer? If you do end up reading my query, and can point me in the right direction, please do so in the comments!