People from NASA and UNAM University in Mexico are studying the feasibility of growing trees on Mars. Growing trees on Mars is currently considered one of the first steps towards terraforming the planet. By pumping a lot of heavy gases onto the planet, such as methane and nitrous oxide, it might be possible to heat the surface of Mars to around 41 °s; F. Certain tree species in Mexico are known to grow at that temperature on a mountain called Pico de Orizaba. Trees are considered to be the 'engine of the biosphere'. Once they start growing, it is believe that the process of terraforming will begin to take care of itself.