Exploring the Boundaries of Life in the Lab with NASA
Article by: Andacs Robert Eugen, on 07 July 2023, at 10:07 am PDT
Delving into the mysteries of life's origins and potential existence beyond Earth involves a multi-faceted approach. While interplanetary probes and space telescopes push the boundaries of extraterrestrial exploration, laboratories on Earth play an equally vital role. Scientists conduct experiments to unravel the chemical beginnings of life, search for evidence of life's building blocks in meteorites, and even simulate environments conducive to exotic life forms. As part of a global effort, NASA scientists strive to comprehend the origins of life on our planet, explore the possibilities of life on others, and develop technology for its detection within our solar system and beyond.
Laurie Barge, co-leader of NASA's Origins and Habitability Lab, focuses on bridging the gap between geochemical environments and the inception of organic chemistry. Through her renowned work on chemical gardens, she recreates the conditions of primordial oceans' hydrothermal vents, investigating how metabolism, a fundamental aspect of life, may have emerged billions of years ago. These hydrothermal vents, resembling "chimneys," could exist not only on early Earth but also on Saturn's moon Enceladus and other "ocean worlds" veiled beneath icy shells.
While time travel to early Earth remains impossible, asteroids offer windows into the infant solar system. Unchanged for billions of years, these celestial bodies serve as time capsules. By studying meteorites, rocks that fall to Earth from space, scientists like Jason Dworkin at NASA's Goddard Space Flight Center examine the composition and chemistry of early planets' building blocks. The analysis of samples from missions like Hayabusa2, NASA's Stardust, Apollo, and soon OSIRIS-REx enables researchers to gain insights into organic compounds and their potential role in the origins of life. Discoveries such as the detection of amino acids in comets provide tantalizing clues about life's early stages.
Titan, Saturn's moon, presents an intriguing possibility for unconventional life forms. With lakes and rivers composed of methane and ethane instead of water, Titan challenges the notion of life as we know it. Laboratory experiments reveal that under certain conditions, organic material can condense from these liquids, potentially leading to lifelike structures. The Dragonfly spacecraft, slated to explore Titan in the 2030s, aims to examine prebiotic molecules and assess their relevance to biochemistry, even if unfamiliar.
Astrobiology in the lab not only investigates the conditions conducive to life but also delves into the very origins of life itself. Gerald Joyce and Tracey Lincoln's experiment demonstrated the possibility of Darwinian evolution within an RNA-based system. Although this system fell short of Joyce's definition of true life, it shed light on the plausibility of an "RNA world" preceding our DNA-based existence. Recent progress in understanding life's components aligns with ongoing explorations of our solar system, including Mars rovers and upcoming sample-return missions. Future targets include the icy outer moons, signifying an exciting era in astrobiology.
With advancements in laboratory research, innovative space missions, and the pursuit of knowledge beyond our planet, astrobiology embarks on a thrilling journey. Whether unlocking the secrets of life's origins or probing the potential for life in uncharted territories, scientists strive to unravel the mysteries that have captivated human curiosity for centuries.