Aliens have been a fascinating subject and there's a growing debate on when they will get in touch with human beings. But if aliens do get in touch with humans how would they do it? Here are some theories....

Laser signals

One of the ways that the little green creatures (that we imagine them to be) will reach out to us is through laser signals. Scientists believe that since lasers can send out signals or messages across large distances, this could be a method they choose. Interestingly, many people have reported seeing large flashes of light in the sky which they believe to be alien signals or UFOs.

Radio waves

Physicists Philip Morrison and Giuseppe Cocconi wrote a paper in 1959 for the Nature journal. They stated then that scientists should look out for radio waves from aliens. Search for Extraterrestrial Intelligence (SETI) have been working on confirming reception of radio waves from outer space. Douglas Vakoch, the president of METI International, told that, "We can speculate as much as we want about whether there's intelligence out there in the cosmos, but unless we find something interesting and do a rigorous follow-up, we'll never know."

Massive constructions

UFO hunters recently claimed that they spotted a 'door' on Mars and some even went a step further abnd said there was a house. UFO hunter Scott C Waring was quoted by Metro UK as saying, "This is absolute 100% proof that a tiny intelligent species once lived on Mars. his is freaking history in the making. This dark doorway into this tiny home was found by Youtube user Luxor2012UFO. This is the most mind-blowing discovery I have seen all week. This doorway is about 3 inches by 6 inches. It's perfect. All its corners are just perfect. This is absolute 100% proof that a tiny intelligent species once lived on Mars."

But others talk about massive constructions that are out there in outer space. Some scientists say that these structures are meant to attract other forms of life towards them. However, no one has found them yet.

Space probes

Another way that extra-terrestrials could get in touch with us is through space probes. Aliens could create space or robot probes and send them out to us. Right now, we don't know what they are capable of so who knows?

Designs of stars

Have you seen how stars suddenly form shapes or dance in s a strange way? These outer world creatures could make the stars dance or form shapes that would send messages out to us. And because stars are visible across large distances, these creatures could be billions of miles away and yet reach out to us.