Scientists' exploration of life in the universe takes many forms and reaches across disciplines. As a pursuit, understanding how life emerges, survives and goes extinct can help inform any number of fields of study—biology, ecology and evolution, to name a few—here on Earth.
Santa Fe Institute Professor Chris Kempes discusses this topic in a public lecture this week. A physical biologist, Kempes says many in his field are naturally interested in astrobiology because of the need to understand the "basic mechanisms of life, the underlying axioms or concepts of life" in order to apply what is learned to a variety of frameworks.
In addition to his own work, which often focuses on studying how biological processes can be applied mathematically, Kempes is part of the Santa Fe Institute's Exploring Life's Origins project, in which scientists across fields collaborate in the pursuit of understanding life in its myriad forms. Scientists have been interested in understanding how life began for at least 200 years, Kempes says, with intensive interest for the last 50.
"We've come to understand a lot about how life evolves and what the process looks like, and have developed a very fine-grained understanding of evolutionary processes," he says. But "there's still complicated questions on how you get something that looks like life from complicated environments; there's a lot of proposals for the origins of life and there's a lot of possibilities."
In his lecture, Kempes will walk attendees through the different ways scientists explore the universe for signs of life. Take Enceladus, for example: Saturn's icy moon, where "there are plumes of water vapor coming off the surface, and some of that water vapor is escaping the moon and some of it is falling down back to the moon's surface as snow," Kempes says. Observations of Enceladus indicates it contains a subsurface ocean and "potentially" what's known as hydrothermal vent systems. To quote National Geographic, these "are like geysers, or hot springs, on the ocean floor."
Discovery of hydrothermal vents in the Galápagos Rift in 1977 is considered a seminal point in the study of the origins of life. Those hydrothermal vent systems, or "black smokers," contributed greatly to the study of microbial life, as they are hospitable places for life to form (a few interesting photos of bacteria will be among the visuals at the lecture).
For Kempes, studying the origins of life involves a variety of pursuits, and has resulted in work that considers general properties for life—from the minimum size of bacteria to the maximum size of specific trees and beyond—that can be applied predictively across physical phenomena. "One of the main things I'm interested in is, what are the general rules or properties of life? And a lot of what that entails is writing down theories for what constrains the types of life that we know and trying to understand what's common," he says.
As for the broader universe, he says, "there are lots of different candidates for existing or past signs of life," as well as emergent discoveries about exoplanets (planets beyond Earth's solar system) that could lead to more as the study of these planets' atmospheres becomes more sophisticated and detailed.
"If you can start to tell in a very detailed way what exists in the atmosphere of these other planets, it opens up a huge range of possibilities of detecting potential signs of life," he says.
Kempes joined SFI as a professor in February, following a fellowship at the institute. A native New Mexican, Kempes finds particular synergy in studying these issues here.
"Both the daytime and nighttime sky is ever present," he says. "It's almost a platitude, but it's inspired people for a long time." Moreover, New Mexico's landscape itself "with rich fossils coming out of different parts of the state, also inspires a different sort of big thinking about deep time."
SFI is notable for its public programming on its research, but I wondered if there was actual scientific value for Kempes in discussing his work with non-scientists. He says yes.
"When you give a talk to the five other people who do exactly what you do … there's a lot of shorthand that's taken for granted," he says. "There's a benefit to that in that it's easy to make progress, … but it's sometimes easy to lose perspective." He continues, "Stepping back and doing a very broad lecture like this does force one to remember all the different things the field thinks about: all the different problems, what the history has been, what the motivation has been. I actually in general think it's a very effective way of doing science."
Life on Earth and Beyond
7:30 pm Tuesday March 20. Free.
Lensic Performing Arts Center,
211 W San Francisco St.,