A Local Search for Distant Life

Research knows no bounds! In the ongoing hunt for life outside of Earth, scientists are learning to observe local environments to help them find similar conditions on other planets. One such environment happens to be right next door in Yellowstone National Park.

Geologist Andrew Gangidine of the University of Cincinnati spends many of his days wading through the geothermal muck of Yellowstone. Here, he is constantly surrounded by bubbling mud vents and gases, which become dangerous after overexposure. Gangidine takes careful precautions not to stay in proximity of the toxins too long. But why does he take the risk at all? The answer is life!

Mud Pot bubbling - Yellowstone National Park

Yellowstone Park’s pools are naturally teeming with bacteria that are kept in an evolutionary stasis by the heat and chemicals from the vents, allowing Gangidine and other scientists to observe what life on Earth may have been like millions (to billions) of years ago. The pools are similar to conditions on the early Earth, when our planet was a hot, volatile place.

Gangidine’s research has been extrapolated to the mysterious, convoluted history of Mars. In 2007, while roaming the Martian surface, the Mars Rover Spirit got its wheel caught in the dusty Martian topsoil. When the wheel remained powered and spun in the dirt, the red dust wore away and revealed a hidden white surface beneath. Spirit’s analysis determined that the deposit was made of opaline silica. Coincidentally, opaline silica deposits also exist on the edges of hot springs in Yellowstone Park. Thanks to this discovery, Gangidine became interested in the possibility of Mars once harboring microbial life.

The shallow trench where Spirit's dragging wheel revealed fine-grained silica.
Credit: NASA

Gangidine hypothesized that if organic compounds could be found in Earth’s geothermal pools, perhaps the same compounds could be found in Martian deposits. His next great opportunity to find out is happening just two years from now, when a new Martian rover will begin making its way to the Red Planet. The Mars 2020 rover will be collecting a variety of samples from an area on Mars not yet explored. With any luck, some of those samples may be crucial in the search for a history of life on Mars.

Until then, Gangidine will continue his research at local hot springs. In the last two years, his studies produced fruitful outcomes; Gangidine found elements including iron, manganese, and gallium within the pools. Iron and manganese can be considered building blocks of life when paired with an assortment of other elements. However, gallium is not typically associated with the formation of life. “Gallium is surrounding these fossils, and we don’t know of another way to explain that other than life is doing it,” Gangidine said.  Currently, he is searching for a multitude of elements that could possibly string together an organic lifeform, but outliers like gallium make it more complicated.

Gangidine’s next research trip will take him out of Yellowstone and into an ancient microbe graveyard in Western Australia. Once there, he hopes to sort through microbial leftovers that have withstood the test of time. The bacterial remains of Yellowstone are only about 14,000 years old, whereas the specimens in Western Australia are about 3.5 billion years old! By studying these ancient remains, Gangidine hopes to learn how ancient bacteria survived on Earth with the hope that NASA can use Mars 2020 to search for evidence of similar conditions on Mars. Gangidine’s research in Australia will hopefully bring us closer to determining the life sustaining environments that may have existed on Mars in the past.

Upper Geyser Basin - Yellowstone National Park