The author of Lonely Planets: The Natural Philosophy of Alien Life, David Grinspoon is a curator of astrobiology at the Denver Museum of Nature and Science as well as the first chair in astrobiology in the Kluge Center at the Library of Congress, a position he took up last November. Pat Trenner interviewed Grinspoon last August.
Air & Space: The Library of Congress announcement of your appointment says astrobiology addresses how life began and evolved and the future of life on Earth and elsewhere — pretty weighty questions. How does astrobiology begin to formulate the answers?
Grinspoon: We break it down into smaller questions that don’t weigh quite as much. In order to address how life began we study the record of life on early Earth, make predictions about what we will find on other planets and then try to test them through spacecraft missions. The future of life we can address, in part, through understanding better how planets evolve. For example, Venus may have gone through an accelerated version of Earth’s distant future when it lost its oceans to the warming sun. By deciphering this history, we may learn what is in store for us and how we will eventually need to adapt.
Any opinion on the best strategy for space exploration? Should we wait for commercial development of man-rated spacecraft or should we rely on robotic craft?
The way things are shaping up, commercial spacecraft will do the more “routine” tasks like taking cargo and humans into Earth orbit, and NASA and other government space agencies will do the more curiosity-driven, envelope-pushing exploration that can’t be expected to turn a profit any time soon, such as building large space telescopes and sending robotic craft to worlds like Venus and Titan. This makes sense to me and seems to be the way things are evolving.
Where in our solar system are we most likely to find signs of life?
We have to explore broadly because we are still profoundly ignorant about life and what it really needs. It seems obvious at least that life needs an active environment with cyclic flows of energy and matter, and probably a liquid medium where biochemistry of some kind can flourish. So I wouldn’t spend too much time or money looking for it on Mercury or the moon or asteroids. Mars is still worth exploring for life, although I think it is much more promising for possible fossil remains of early life from the time when it was more Earth-like with flowing water on the surface. My favorite places to look for life that may exist today are Saturn’s moon Titan, which has lakes of liquid methane, beneath the surface of Jupiter’s moon Europa where there is a large ocean of liquid water, and even in the clouds of Venus which are a watery, albeit chemically challenging environment. Saturn’s moon Enceladus seems to have liquid water but not necessarily the kind of globally cyclic activity that may be necessary to support a biosphere.
Would we recognize truly alien life if we found it?
I think, after a double-take or two, we would because I think life will always alter its environment in very noticeable ways, as life does on Earth.
You mention the 1989 Voyager 2-Neptune encounter, during which you watched the first close-ups of Neptune's moon, Triton, appear at the Jet Propulsion Laboratory, as a high point in your career. What is the next personal milestone you anticipate?
My work at the Library of Congress will allow me to get down in book form some ideas I’ve been developing for a long time about how human life fits into planetary evolution and how this illuminates our current choices. I’m very excited about that opportunity. As far as planetary exploration goes, I’m thrilled to be on the science teams of both the European Venus Express, which is currently in orbit around Venus and the Curiosity Rover that just landed successfully in Gale Crater on Mars. This is going to be quite an adventure. I’m also determined to be part of a future American Venus mission. We have several that are in various stages of the proposal process and future exploration of our sister planet is absolutely essential for our ability to contextualize the evolution of our own planet. I want to help make that happen.
While on loan to the Library of Congress, will you have to forego performances with the Denver planetarium's House Band of the Universe, which, in your words, plays “groove-based jazzy spacey afro pop?”
No! In fact we have just been funded by NASA to do a limited national tour of our “Life Out There” musical planetarium show. So I will spend some time working with the House Band of the Universe even while I am in Washington for a year. I’m hoping that transporter beam technology becomes available soon, as this will make it all a lot easier.
Do Carl Sagan and Jerry Garcia share equal billing as your inspirations?
They both loom large in my personal galaxy. Everyone in my field was inspired by Carl Sagan, and I also had the privilege of knowing Carl very well, as a family friend, an uncle figure, and later as a mentor and colleague. There is nobody alive today who combines his exploratory intellect with his ability to connect science to the masses. It was a unique package and gives a lot of us something to strive for. I didn’t know Garcia personally, although I did meet him a couple of times and certainly spent (some would say misspent) many hours in various clubs, halls and stadiums listening to him play. My impression was that he was very kind and had a deep and generous intelligence. It’s quite affirming to meet your heroes and have them seem wonderful up close and personal. Creatively he broke boundaries and invented his own rules. He did for musical genres what astrobiology is trying to do with separate scientific disciplines: merge them and make something new, worthwhile and larger than the sum of the parts.
Your critique of the 2004 movie The Day After Tomorrow: It “sucked giant hailstones.” Are there any popular films you can commend for attempts at scientific accuracy?
Did I say that? How intemperate! That movie cut some serious corners. The quality of science in films is often quite poor. The model is that producers hire a “science advisor” who comes in after the story is mostly done and gives them some nerdy jargon to make the film seem more credible. There are web sites that advise aspiring science advisors to “Remember, the story comes first”. In other words, it doesn’t matter if the whole thing is based on a premise that is stupid and creates misconceptions, as long as you can sneak in some science lessons or vocabulary. Well, what about actually having the science drive the story? That’s what has shaped the few really excellent science fiction films. The best is 2001: A Space Odyssey. Other good ones are Contact, The Andromeda Strain, Blade Runner, and Gattaca. These filmmakers started with the science and built a story around its wildest implications.