"Now we see Mars as a place where we used to have life," Green said. "It will get better and better."
Mars is more like the earth than any other planet in the solar system, making it the second planet that humans may live in. There are many natural beauty on this planet: a Grand Canyon, which is almost the width of the United States, and a volcano with the size of Arizona.
Green said that the planet can provide a new perspective for human beings to examine life.
At present, NASA plans to send people to Mars by 2040. But it depends on a lot of factors.
Green outlined some of the obstacles that exist.
We must solve the landing problem. NASA is now able to land a ton of aircraft on the surface of Mars. But for humans, landing on Mars requires about 10 tons of aircraft. The device also requires a precise landing, avoiding mountains, hills, or rocks.
We need to take off from Mars. When humans land on Mars, it should not be a one-way ticket as it is now. That's why NASA is developing Mars 2020. "at some point in the next decade, we plan to launch and return from the surface of Mars."
We need to wear spacesuits all the time. The weather on Mars is extreme. The temperature difference between Monday and Tuesday could be 170 degrees. The average temperature on the surface of Mars is well below zero. The main content in the air is carbon dioxide, which is good for planets and bad for human survival.
We must get used to sandstorms. About every 26 months, the summer on Mars comes. Summer on Mars means dust storms. This tiny dusty castle can turn the day yellowish and last for months.
We need to build a good infrastructure. "people who go to Mars are real pioneers," Green said. The first humans on Mars needed to grow and create food sources. Scientists believe that beans, asparagus and potatoes are effective crops for Martian soil. Human habitat also needs to be built. Green says a 3 D printer may be able to use dust from the surface of Mars to create habitats.