Ever since the environmental movement was sparked by photos of the whole Earth taken by astronauts onboard Apollo Lunar Modules, I've seen planetary exploration as an extension of a reverence and care for Earth.
Titan has rivers and lakes of liquid methane and ethane, methane weather systems of clouds and storms that mirror Earth's hydrologic cycle, and seasonal cycles that rival Earth's in complexity.
As a young planet, Venus was losing hydrogen rapidly to space. The oceans boiled off, and after some period of time, perhaps 600 million years, there was no surface water.
The more we look at the kinds of soils and the nature of the atmosphere and the polar caps, it all adds up to tell us that some liquid, which we very much believe was water, did flow in abundance on Mars in the past.
NASA, and all the other spacefaring nations of the world, have agreed to a set of 'planetary-protection' principles, aimed at preventing the accidental contamination of another habitable world with organisms from Earth.
We're going to get off fossil fuels, no question. We may not do it quickly enough to avoid some pain, and I'm quite worried about that. But by the 22nd century, there's no way we'll be on fossil fuels.
When I first went to college, I went into physics, and my goal was to help perfect nuclear fusion so I could solve the energy crisis and global warming. I probably would have done it, too, if I'd stuck to it.
We definitely don't want to go through another Ice Age or another natural cycle of global warming. Both happen over a long period of time. It would be disastrous for our civilization, and not just for us but many other species.
What I'm interested in is the conversations going on about the Anthropocene and what it means to view ourselves as a part of Earth's geological history.
We have to learn to become a new kind of entity on this world that has the maturity and the awareness to handle being a global species with the power to change our planet and use that power in a way that is conducive to the kind of global society we want to have.
Earth's biosphere gave birth to humans and our thoughts, which are now reshaping its planetary cycles. A planet with brains? Fancy that.
Among the plausible niches for extraterrestrial life in our solar system, the clouds of Venus are among the most accessible and the least well explained.
One of the weird things about modern physics is that we do find there are apparently these other dimensions that we don't directly experience that explain some aspects of the overall geometry and reality of our universe.
I think Pluto has to be considered among the places in the solar system that are possible homes for life.
As a kid, I became a total SF geek. It started in the 5th grade with Asimov's 'Lucky Starr' series of what would now be called 'young adult' novels of adventures in the solar system.
There's eco-pragmatism, where you recognize, 'Yeah, we live on a planet that's permanently altered by humanity, and rather than seek to return to or preserve pure wilderness, we recognize that's an illusion, and we proceed under the new knowledge that we live, in fact, in a human-dominated planet.'
The future peopling of Mars is much more than a scientific endeavor. It is a step of historic and spiritual importance for the human race.
It is said that Mahatma Gandhi, when asked about Western civilization, remarked, 'I think it would be a good idea.' That's how I feel about intelligent life on Earth, especially when I think about the question of what truly intelligent life might look like elsewhere in the universe.
If we gutted NASA Earth Science, it wouldn't be NOAA or some other agency that would take the lead. It would be the Chinese and the Europeans and the Japanese.
I don't see it as coincidence that the great acceleration of the Anthropocene influences on Earth came during the same decades as our first exploration of the other planets.
