Six volunteers are about to find out what it would be like to live on Mars without ever leaving the Earth. Three men and three women will spend eight months living in a special place on the side of a volcano in Hawaii. They are part of an experiment that is designed to mimic life on Mars. Their mission began on October 15, 2014. NASA says it could send astronauts to Mars as early as the 2030s. The mission would take more than two years, so NASA needs to know how people would react to living in a small group, isolated from the rest of the world, for such a long time. Some people may become depressed or bored living under those conditions. By studying people living in similar conditions here on Eares NASA hopes to learn how to choose the most suitable people for a space mission, and how to help them get along. They will live in a two-story building. The ground floor is about 86 square meters, roughly the size of a small two-bedroom apartment. It includes shared areas like kitchen, dining room, bathroom, laboratory and an exercise room. The upstairs is less than half the size of the downstairs. It contains another bathroom and six small bedrooms. The building is located in an abandoned quarry about 2,400 meters up the side of Mauna Loa, the second biggest volcano in the world. It is constantly monitored for signs of volcanic activity. NASA chose the location because the appearance looks very similar to Mars. To make it more like being on Mars in the future, they are only able to communicate by email during the experiment. Meanwhile, there will be a 20-minute delay between the time when a message is sent and that when it is received. When they go outside, they will have to suit up in full spacesuits, just as if they were on Mars. The commander is Martha Lenio, a 34-year-old Canadian. During the mission, she will run experiments on growing food. The other members have backgrounds in physics and so on. None of them are astronauts. Mauna Loa was chosen as the experimental site because   _  .
it is located near a rocket base other people can hardly find the location its landscape is so much like that of Mars it is a safe place to conduct the experiment