David Grinspoon Quotes

As long as we are a single-planet species, we are vulnerable to extinction by a planetwide catastrophe, natural or self-induced. Once we become a multiplanet species, our chances to live long and prosper will take a huge leap skyward.

This afforded an opportunity for a close encounter with Earth as it might appear to an alien spacecraft, and Carl Sagan proposed using this as a "control experiment for the search for extraterrestrial life by modern interplanetary spacecraft." The instruments detected the spectral signature of the chlorophyll from green plants, and signs of an obviously life-altered atmosphere. As Sagan and colleagues wrote in their paper "A search for life on Earth from the Galileo spacecraft" published in Nature, they found evidence of abundant gaseous oxygen, a widely distributed surface pigment with a sharp absorption edge in the red part of the visible spectrum, and atmospheric methane

Earth would stand out as strange and perturbed, with something in the air that geology and chemistry alone could not explain, with some huge ongoing, active chemical disturbance.

The planetary perspective provides a kind of out of body experience for us - hovering in orbit and watching ourselves sleepwalk through a slow disaster of our own making. Now, can this experience help us to shake ourselves awake? For virtually all of its history Earth has evolved without us, and we have always seen ourselves as autonomous actors on a passive planetary backdrop. But now we are beginning to see that our futures - those of humanity and of planet Earth - are tightly conjoined. If human civilization is to persist and thrive we will need a completely different view of our planet, and of ourselves, in which we acknowledge both our deep dependence and our increasing influence.

Before we go there and set up greenhouses, dance clubs, and falafel stands, let's make sure that, in some subtle form that could be harmed by the human hubbub, life does not already exist there. If not, then by all means build cities, plant forests and fill lakes and streams with trout
bring life to Mars and Mars to life. We'll then be the Martians we've been dreaming about for all these years.

The planet Mars
crimson and bright, filling our telescopes with vague intimations of almost-familiar landforms
has long formed a celestial tabula rasa on which we have inscribed our planeto-logical theories, utopian fantasies, and fears of alien invasion or ecological ruin.