If the message has not been emphasised enough already, there are hundreds, most likely thousands, of possible habitable environments on worlds throughout our Solar System and beyond. But before we visit these places and possibly consider making changes to them so that they can host humanity, we may want to start by paying them the courtesy of protection from us while we investigate them. Space agencies all over the world have signed up to a very important programme of Planetary Protection, which scientists hope will preserve any possible life forms that do exist outside our planet from contamination by terrestrial organisms hopping a ride on incoming spacecraft. In turn, we are also committed to protecting the Earth from contamination by alien life should such a craft laden with samples return home. This responsibility is not taken lightly by humanity. We understand and appreciate the need to ensure that we are not interfering with these natural pristine environments while still powering forwards with our exploration of the cosmos. Missions to Mars are especially singled out by The Committee on Space Research (COSPAR). Since it has special regions within which terrestrial organisms could readily propagate, and areas thought to have an elevated potential for existence of Martian life forms. This applies to any region on Mars where liquid water occurs, or can occasionally occur, and is of course based on our current understanding of the requirements and conditions that are just right for life.
This talk of extraterrestrial life, habitable environments, moving to the Moon, humans colonising the Galaxy, and growing flowers and eating asparagus on Mars is fantastical and exciting, but we must not overlook and forget about our just right planet, to which we owe our very existence. We are designing habitats that will enable us to survive on Mars and the Moon and technologies to search for alien life forms despite the fact that we do not yet understand how life came to be on the Earth and have been unable to colonise some of the most remote places on our own planet that are lush in comparison to those found throughout the Solar System. Humanity is not using the only truly habitable planet we know of to its fullest potential, but are instead taking a liberty with the lessons it has to teach us. Yet planetary exploration and planetary preservation have the same goal. If we can find means by which to colonise and inhabit the most inhospitable places on the Earth, it will aid our exploration of other worlds, and in so doing will help us to better use and preserve our own.
Whether we are searching for just the right home to live in, just the right school to send our children to, just the right moment to take the next step forwards in our lives, or just the right planet to house another form of life in the cosmos, humanity is constantly searching for its just right, as Goldilocks did. We are exploring the Solar System but found that Mercury and Venus may be too hot and Mars and the outer icy worlds may be too cold. We have eagerly turned our eyes to the exoplanets and exomoons of distant solar systems, hopefully watching and listening for any signs of life. Yet the just right for humanity and life as we know it today is the Earth – who knows what it might be in the future.