Quotes from David Grinspoon

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 planetological theories, utopian fantasies, and fears of alien invasion or ecological ruin.

Our most valuable resources - creativity, communication, invention, and reinvention - are, in fact, unlimited.

We're going to stop looking at Earth from orbit because we don't like what we are seeing and the conclusions that leads us to? That's nonsense.

Earth is going to lose its oceans in the future, just as Venus did in the past. How long planets retain their oceans is a function of distance from the sun, all other things being equal.

Venus and Mars are our next of kin: they are the two most Earth-like planets that we know about. They're the only two other very Earth-like planets in our solar system, meaning they orbit close to the sun; they have rocky surfaces and thin atmospheres.

I'm a strong advocate of new missions to Venus.

We don't know that Venus had oceans, but there's every reason to believe it did.

A lot of the science fiction that I grew up reading was written when we still thought that Venus might be an oceanic planet.

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.

If you were on the surface of Venus, assuming you could see the Sun, which, you know, would be hard because it's so cloudy there, but the Sun would actually rise in the west and set in the east. And, it would do so very, very slowly, because the planet rotates incredibly slowly.

It's one of the big mysteries about Venus: How did it get so different from Earth when it seems likely to have started so similarly? The question becomes richer when you consider astrobiology, the possibility that Venus and Earth were very similar during the time of the origin of life on Earth.

It will be a long time, if ever, before we get to study Earth-like planets orbiting around other stars, so really, the study of Venus and Mars is the best opportunity that we have, and can imagine having anytime in the future, to understand the evolution of Earth-like planets.

It's quite possible there's as much lightning on Venus as on Earth.

I do comparative studies of climate evolution, and the interactions between planetary atmosphere and surfaces and their radiation environment, and try to understand the environmental factors that can affect a planet's habitability and how they change over time.

I do a lot of work with NASA and am involved in research projects studying planetary evolution, Earth-like planets, and potential conditions for life elsewhere.

I intend to apply the perspective of astrobiology, which is a deep-time way of looking at life on Earth, towards the question of the Anthropocene. What does the human phenomenon on Earth look like viewed from an interplanetary perspective?

The reason you see so many volcanoes on Venus is partly due to the fact that there's virtually no erosion there. So on Venus, you're seeing features, some of which are hundreds of millions of years old on the surface. On Earth, we do not see any surface features nearly that old - you only see much more recent features.

We can look out on an alien landscape that no one has seen before and find it beautiful.