I am undecided as to whether I believe life exists elsewhere in this universe. Its hard not to, but it seems so unlikely that there is. What are the chances of there being a habitable planet like earth? Very slim. We have so much to discover about the universe, and our own galaxy as far as that goes. Its impossible for me to comprehend how large the universe is. Even our galaxy. When i look at the Milky Way i think of Earth as a small dot, but in reality it is much, much, much smaller than a visible dot.
If the universe is so vast, how could there not be life other than that on Earth? Earth is a perfect environment for life, but seeing that some bacteria live in extreme heat, cold, and salinity, life is pretty good at making the best of what it's given.
The life form could be only a worm, or a bacteria, or a lizard of sorts. When most people think of alien, they think of something along the lines of a big headed martian, or a Twi'liek from the Star Wars universe or maybe an Asari from Mass Effect... but what are the chances? Most likely it would only be an instinct based animal that only lives to eat and reproduce.
Most of Earth's biomass is composed of organisms 1mm in size or less, and with microorganisms evolving up to 4 billion years ago, I would be surprised if our first look at alien life wasn't microscopic.
So lets say we do happen to come in contact with an intelligent life form. Stereotypically aliens are far more advanced than us Humans, they have mastered space travel, can read our thoughts, and are basically intellectually superior.
Just because they're aliens doesn't mean that they can break the laws of physics.
Well what if they were hundreds or thousands of years behind in technology? And what would they look like? Would they be smooth skinned humanoids or 10 legged lizard creatures with 2 tails?
Remember, although it's hard to do you can't compare anything human to possible alien life. "Years behind in technology" could be completely irrelevant to their status as living beings. As said before, they could be microscopic or larger than dinosaurs. We can only imagine at this point.
Its sad to know we wont come in contact in any of our lifetimes should there be life out there somewhere.
I wouldn't throw in the towel yet.