Why do UFO's sometimes refer to as Martians?

I think people believed that those UFOs came from our neighbor planet,Mars.they can easily go to earth because we are the nearest planet to "their" planet.also,there were some studies (according to NASA) that there are "evidences" of life in Mars.unless proven that there are "signs of life" in other planets,then there will be another names for UFOs.Jupiterians or Venusians,maybe.

Well i think because mars is the closest planet to earth. I know mercury is also close to earth, but i think the planet is less popular then mars. And people will not think they come from the moon because neil amstrong has been there ( which many people say it just a big hoax from nasa ) and found anyone or any alien. Ok, thats it from me.

This goes back to Victorian times - improvements in telescope design etc meant suddenly everyone was looking at the stars. The discovery of "canals" on Mars created excitement these canals might be artificial, i.e. made by Martians. [i]"In 1877 Giovanni Virginio Schiaparelli, an astronomer at the Milan Observatory in Italy, announced a finding that would have an unexpected though significant impact on astronomy. He announced the observation of "canali" on the surface of Mars. Though the most accurate translation of "canali" would have been channels, it instead got translated to canals. With the recent completion of the Suez Canal the interpretation was taken that to mean large scale artificial structures had been discovered. In other words, evidence of intelligent life." [/i] Although there was a lot of scepticism, a few noted intellects did jump on the band wagon, including Percival Lowell (a noted astronomer) and a certain Mr H G Wells, who coined the phrase "Martians" when he wrote his famous novel "War of the Worlds" - still the most read science fiction book today. His astronomer character (at the start of the book) was based on Percival Lowell, whom he much admired. So now you know.