I will defend the NASA Earth Science Division with everything I've got.
We're pretty sure there's plenty of organic material on Pluto. The atmosphere is largely methane, and in sunlight, methane builds organic molecules. We see reddish stuff on the surface that we think is organic material.
In order to have a decent chance to be a communicating species, you would have to learn to think and plan and act over time scales of a century or a millennium.
We have all this very clever technology and all these abilities to manipulate the world in all these ways, yet we are faced with the very real question of whether we can be sustainable on this planet - whether or not, in fact, we can endure.
The basic ability to not wipe oneself out, to endure, to use your technological interaction with the world in such a way that has the possibility of the likelihood of lasting and not being temporary - that seems like a pretty good definition of intelligence.
I think that an advanced planetary civilization will modify their own planets to be more stable, to prevent asteroid impacts and dangerous climate fluctuations.
I'd been politically active ever since my parents wheeled me in a stroller in a 'ban the bomb' march in Boston in 1963.
A lot of the science fiction that I grew up reading was written when we still thought that Venus might be an oceanic planet.
We've almost been wiped out as a species many times, going back millions of years, and we've survived by reinventing ourselves and enlarging our circles of awareness, inventing new technologies and social structures.
Even cynical, selfish people will realize, one way or the other, that it's not in their self-interest to act in self-destructive ways.
Even as our unwitting alterations to Earth's carbon and hydrological cycles slowly make storms more damaging, our ability to monitor our planet from space and make reliable short-term forecasts have equipped us enormously to withstand them.
Through space-based climate studies, my colleagues and I have learned that a stable and comfortable climate is not something to take for granted.
Thinking about the new epoch - often called the Anthropocene, or the age of humanity - challenges us to look at ourselves in the mirror of deep time, measured not in centuries or even in millennia, but over millions and billions of years.
Humanity has at least a dim, and growing, cognisance of the effects of its presence on this planet. The possibility that we might integrate that awareness into how we interface with the Earth system is one that should give us hope.
The mature Anthropocene begins when we acquire the ability to live sustainably and become a lasting presence on this world.
Responsible global behaviour is ultimately an act of self-preservation of, by, and for the global beast that modern technological humanity has become.
Mars does not belong to 'America,' nor to Earth, nor to human beings.
My high-school friends and I felt part of a community of smart, forward-looking space and technology freaks.
Whenever I see a nighttime picture of Earth from space, with its glowing lights, I am stirred by its beauty.
Earth is a stunningly lovely planet for so many reasons. Among these is the wondrous presence of curious, artful, inventive humanity.
