Alien Worlds and the Fate of Earth
By Adam Frank
262 pages. WW Norton & Company. $26.95.
Near the beginning of his engaging and accessible book “Light of the Stars,” Adam Frank sounds a familiar environmental alarm bell: “It’s like we’ve been given the keys to the planet. We are now ready to knock it off a cliff. Frank’s interesting new idea is to combine a history of climate change on Earth with recent astronomical data indicating the likelihood of large numbers of habitable planets in the universe, to suggest that we can strengthen our resolve to get rid of our bad environmental habits by observing our earth planet. civilization from a cosmic point of view. For example, he cites evidence that Mars once had liquid water and a thick atmosphere – conditions that support life. Apparently the climates can change drastically over time.
An astrophysicist at the University of Rochester and founder of the NPR 13.7: Cosmos and Culture blog, Frank argues that we earthlings should embrace a new narrative of our history and our future. Rather than simply continuing to procreate and exploit our abilities and resources on Earth, we should recognize that we and our planet are evolving. whole. Our planet could be thought of as a unique living organism, invented Gaia by scientist and futurist James Lovelock. We have entered a new geological era, what biologists call the Anthropocene, in which we, Homo sapiens, are changing the planet, and our survival depends on understanding this symbiosis. Frank asks: Have other civilizations elsewhere in the universe, evolving through their corresponding Anthropocenes, managed to survive? And by what strategy? Of course, we don’t know the answer to these questions, as we have yet to see evidence of such civilizations beyond our own planet, and we may not soon. (“Soon”, here, is measured in tens of thousands of years.)
“Light of the Stars” traverses a vast terrain of geological, biological and astronomical sciences, focusing on the history of Earth’s climate change and the factors driving these changes, and includes portraits of scientists such as Carl Sagan, Frank Drake, Lynn Margulis and others. Frank animates the text with his passion, his opinions and even some of his own projections of our possible destinies. He is also a good storyteller. We see the great physicist Enrico Fermi and several of his colleagues walking for lunch on the campus of Los Alamos National Laboratory on a hot summer day in 1950, weaving their way along a “path lined with pine trees and junipers”. In the middle of lunch, Fermi asks the question: “But where are they? being the aliens. If there are so many other life forms in the cosmos, why haven’t we seen any? Could it be that such civilizations destroy themselves (by nuclear war or climatic devastation) after only a few thousand years?
The book is divided into two parts. One is a review of environmental science and a history of climate change on Earth. The other concerns the new field of astrobiology, with the results of the Kepler satellite, launched in 2009 with the specific mission of searching for undiscovered solar systems, but which also allowed researchers to identify which of these exoplanets were “habitable zone planets” – those the right distance from their central stars to have liquid water. Here we learn, for example, that about 20% of all stars have habitable planets and that the universe is full of “super-Earths”, planets with masses somewhere between the smaller Earth and rocky and gaseous and icy Neptune.
While both parts are interesting, I don’t entirely agree with Frank’s overall thesis that they’re related components of the same story. Isn’t the imperative to stop our life-threatening march toward annihilation through human destruction of the environment the same regardless of extraterrestrial life? We don’t need to be part of the Galactic Empire to understand the urgency of our situation here on Earth.