David Grinspoon

Mars does not have an atmosphere and does not have a magnetic field today, so the planet doesn't have the protection from radiation that our atmosphere and magnetic fields provide us on Earth. ”

I think that an advanced planetary civilization will modify their own planets to be more stable, to prevent asteroid impacts and dangerous climate fluctuations. ”

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. ”

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. ”

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. ”

I'd like to jump a couple hundred years into the future and work with the scientists who are getting back the first information from our probes to planets orbiting nearby stars. ”

Now, humans have become a dominant force of planetary change and, thus, we may have entered an eon of post-biological evolution in which cognitive systems have gained a powerful influence on the planet. ”

Even as a kid enthralled with science fiction, I wondered about the role of people in the long-term evolution of the Earth, the far future and the fate of humanity. ”

Radiation is one of the important factors in evolution. It causes mutation, and some level of mutation is actually good for evolution. ”

I'm an astrobiologist, and I come from a planetary science background, so in a very broad sense, I study the evolution of planetary environments. ”