For thousands of years, people have looked up at the night sky and wondered, “What’s up there? Will human beings be able to go there someday?”
　More than a hundred years ago, astronomers first looked at Mars, a bright red star, through telescopes. They noticed many lines on the surface. The lines were thought to be canals, perhaps made by some kind of intelligent beings. Some people imagined that Martians looked like an octopus. They thought they must have big heads and be super-intelligent. They must also have long, thin legs and arms due to the weak gravity on Mars. Until just a few decades ago, some people still believed that Martians looked like that.
　About fifty years ago, a spacecraft landed on Mars for the first time and sent photographs back to Earth. People were anxious to see what the planet looked like and what, if anything, lived there.