Aliens are there ?

In the Milky Way alone, there are 60 billion planets that could be home to alien life -- and that life could take any fantastic form, ranging from massive icebound microbial networks, to bioluminescent underwater predators, to highly advanced robot races.

At least those are some of the imaginings in "Aliens: The Definitive Guide," a two-hour special airing Sunday at 8 p.m. ET on Discovery Canada as part of Aliens Week.

The project's goal is to establish a benchmark on what extraterrestrial life could look like, where it is most likely to exist and whether it will find us before we find it.

And, of course, there’s the questions of whether alien life even exists in the first place.

"Some scientists say that perhaps we are the only life forms in the universe," says Dr. Michio Kaku, a theoretical physicist at the City University of New York, and one of the experts cited in "Aliens."

"Give me a break. I mean how many stars are there out there in the universe anyway? The Hubble space telescope can see about 100 billion galaxies, that’s the visible universe. Each galaxy consists of 100 billion stars... There definitely are aliens in outer space, they're out there."

Directed by Britain's Mike Davis, "Aliens" was a co-production between Montreal's Handel Productions and the U.K.'s Arrow Media -- with special effects by Montreal's Mokko Studio.

Davis, who comes from a visual effects background working on computer graphics-heavy projects, said it seemed like the right time to embark on such a project.

He said new technology such as the Kepler space telescope is allowing astronomers to discover more new planets than ever before. And some of them lie in the so-called "goldilocks" zone, where life could theoretically exist since the conditions are “just right.”

As a result, Davis said, the possibility of alien “first contact” appears more likely than ever.

"It felt like now was a really good time for our audience to find out about lots of exciting areas of science -- very, very credible science where there are possible breakthroughs taking place when it comes to the discovery of life off the Earth," Davis said in an interview from London.

"We're chalking up lots of planets: we know how big they are, how dense they are, we can make certain assessments about what the chemistry of their atmospheres are like. We're nominating Earth-like planets all the time that seem to have conditions that might be suitable for life."

The project features some of the world's leading experts in their fields, from theoretical physicists to planetary scientists and astrobiologists -- all of whom share their visions of the many possible forms alien life could take.