Studying lake deposits in Idaho could give scientists insight into ancient traces of life on Mars
Does life exist elsewhere in the universe? If so, how do scientists search for and identify it? Finding life beyond Earth is extremely difficult, partly because other planets are so far away and partly because we are not sure what to look for.
Yet, astrobiologists have learned a lot about how to find life in extraterrestrial environments, mainly by studying how and when the early Earth became livable.
Contained within northern Idaho’s Clarkia Middle Miocene Fossil Site are sediments that preserve some of Earth’s most diverse biological marker molecules, or biomarkers. These are remains of past life that offer glimpses into Earth’s history.
An ancient lake
About 16 million years ago, a lava flow in what would one day become Clarkia, Idaho, dammed a local drainage system and created a deep lake in a narrow, steep-sided valley. Although the lake has since dried up, weathering, erosion and human activity have exposed sediments of the former lake bed.
The lake’s depth created the perfect conditions for protecting microbial, plant and animal remains that fell to the lake’s bottom. In fact, the sediments are so well preserved that some of the fossilized leaves still show their autumn colors from when they sank into the water millions of years ago.
Today, ancient lake beds on Earth are becoming important settings for learning about habitable environments on other planets.