Roughly two-thirds of Americans (65 percent) believe that intelligent life exists on other planets, according to researchers at Pew.
Which begs numerous questions, including: If there is life, where is it? Where, exactly, should we be looking? What, exactly, does intelligent life look like?
Across the country, scientists are asking these questions, constantly pondering the existence of life elsewhere in the universe and the methods to search for it. However, the vast distances between planets and the ambiguity surrounding the signs that should be actively sought out make the discovery of extraterrestrial life a truly unenviable task. As you read this, NASA is actively investigating the surface of Mars for any potential indications of life. A little closer to home, however, an interdisciplinary research team is utilizing a lake in Idaho to replicate the ancient environmental conditions on Mars.
Why?
Because the lake contains sediments that retain some of Earth’s most diverse biological marker molecules, known as biomarkers. These biomarkers are remnants of past life that provide insights into Earth’s history and the possibility of life on Mars.
In a fascinating piece that recently appeared in The Conversation, Robert Patalano, a biologist and biomedical scientist at Bryant University, expertly laid out why the examination of the lake makes complete, scientific sense.
Patalano, one of the scientists studying the lake, describes how, roughly 16 million years ago, a lava flow blocked a local drainage system in what is now Clarkia, Idaho, forming a deep lake in a narrow valley with steep sides. Despite the lake having dried up over time, sediments from its former bed have been exposed due to weathering, erosion, and various human activities. For over forty years, research teams like his own, have utilized fossil remains and biogeochemistry to reconstruct the past environments of the Clarkia Miocene Lake area. For the uninitiated, the Miocene Epoch was a time of warmer, global climates that saw the emergence of ecosystems like kelp forests and grasslands.The lake’s depth, according to Patalano, provided ideal conditions for preserving microbial, plant, and animal remains that settled at the lake’s bottom. In fact, he adds, the sediments are remarkably well-preserved, with some fossilized leaves still displaying their autumn hues from millions of years ago when they descended into the water.
Ancient lake beds on Earth are now recognized as significant locations for studying habitable environments on other planets. The lake sediments in Clarkia, for instance, contain a range of ancient biomarkers, notes the scientist. These biomarkers, whether individual compounds or groups of compounds, provide valuable insights into the functioning of organisms and their surroundings in the past. Since the discovery of the Clarkia fossil site in the early 70’s, multiple research teams have utilized advanced technologies to analyze different biomarkers. Among the biomarkers found at Clarkia are lignin, which serves as the structural support tissue in plants, lipids such as fats and waxes, and potentially DNA and amino acids. By comprehending the origins, history, and environmental factors that have contributed to the exceptional preservation of these biosignatures in Clarkia, Patalano’s team may also be able to make predictions about the potential preservation of organic matter in ancient lake deposits on Mars.
Interestingly, he adds, Clarkia and Jezero, a huge crater on the Red Planet, share numerous, rather striking similarities.
For example, both locations, some 140 million miles apart, feature ancient lake deposits formed from silica-rich, basaltic rock in a climate characterized by high temperatures, high humidity, and a carbon dioxide-rich atmosphere. At Clarkia, these conditions have led to the preservation of microbial biomarkers within the ancient lake. Patalano emphasizes the fact that his team is currently working on establishing criteria for biomolecular authentication. This involves developing methods to determine whether ancient biomarkers found on Earth, and potentially on Mars, are genuine indicators of past life rather than recent contamination or non-biological molecules. To achieve this, they are analyzing biomarkers from fossil leaves and sediments at Clarkia and conducting laboratory experiments using Martian simulants that replicate the chemical and physical properties of the lake sediments in Jezero Crater. Through their exhaustive research on the sources, history, and preservation of biomarkers associated with Clarkia’s ancient lake deposits, Patalano and his colleagues aim to create a number of novel approaches for analyzing the samples collected by NASA, once it;s examination of Mars is complete.
If the truth is out there, an unlikely source – a lake in Idaho – may help us identify it.
