If one looked for a place on Earth resembling the conditions on Mars, scientists found that Mexico’s highest (dormant) volcano would fit. Now pine forests growing on slopes of the 13,780 feet (4,590 m) snow-capped Pico de Orizaba are investigated to see if trees could grow on a warmed Mars, as part of a vision of turning the chilly red planet into a human habitat in the future. NASA is collaborating with Mexican universities to see if by warming up Mars by employing heat-trapping gases, increasing the air pressure and starting photosynthesis, they could create an atmosphere friendly to oxygen-requiring life forms, trees being a first important step. In Pico de Orizaba, which is also Mexico’s tallest mountain, trees grow at higher altitude than anywhere else on the planet. “It sounds like science fiction, but we think it’s feasible, said Rafael Navarro-Gonzalez, professor at Mexico City’s UNAM University, who’s been studying for nine years Pico de Orizaba’s pine forests. “We have experienced warming our planet with greenhouse gases, but on Mars we could do it faster with more powerful gases,” he said. “The first human mission to Mars is seen 10 to 15 years away, and the warming-up process could start 50 years later,” said NASA scientist Chris McKay. Greenhouse effect gases like methane or nitrous oxide could rise Mars temperatures to 41° F (5° C) from – 67° F (-55° C) now;at these levels trees grow.