For NASA, the search for extraterrestrial life begins on Earth

New user interface They wouldn’t have the opportunity to explore the Aurora Field during this expedition, but the chimneys weren’t too far-fetched. That same evening, in cooperation with the movements of the ice floe, the icebreaker had the right of vertical passage of the hydrothermal field, towing a modern camera just above the ocean floor. As the images revealed, Aurora was home to a massive black smoker, a crater about two meters wide through which super-hot sulphide minerals flowed. On the other hand, Aurora was a depopulated zone in the realm of hydrothermal vents, as Eva Ramírez Llodra, the mission’s deputy scientific director, explained to me. We spotted only a handful of snails and crustaceans, and no sign of the amazing tube worms or molluscs commonly found around other abyssal vents. Despite everything, in the midst of this devastation a garden of glass sponges flourished. Often relegated to the status of barely living organisms, these oceanic ornamentals were at first glance the only organisms abundant in the region. Their skeletons are composed largely of silica, rather than traditional calcium carbonate, and not without reason. Deep down, silica is a widespread element, and life has found a way to use it through these strange sponges.

Despite all the problems encountered on this journey, the group was able to make their first visual contact with Aurora. The chimneys were active and more mysterious than expected. The largest smoker on the field was also the largest black smoker the German had ever observed during his career.

The Arctic Ocean is sometimes colder than its counterparts in the solar system. For a cautious person like me, it’s not always fun. However, the damp, penetrating cold of an Italian cave proved much worse. He slid deep inside me and refused to leave. Why don’t the solar system’s incubators of life provide a more tropical climate?

Last February, I visited the Frasassi Caves in central Italy, accompanied by scientists tracking the trail of the most mysterious creatures on the planet: microbes living in the cave’s groundwater. In these toxic, oxygen-poor waters live these unlikely collections of slow-burning water that reacts with rocks, producing metabolic fuels like hydrogen sulfide and methane, just like the organisms associated with chimneys and oceanic hydrotherms.

Scientists believe that these chemical reactions could exist on icy moons. They also suspect a certain similarity between the chemical environment of Frasassi and that of the first oceans on Earth, in which the seeds of terrestrial biology may have been planted. “When Earth was born, it was a completely different planet,” says Jennifer McAlady, a microbiologist at Pennsylvania State University and a regular explorer of the cave for more than 20 years. “If we believe that this aquifer resembles Earth’s early oceans, and that it shares commonalities with the oceans of other planets, it is the perfect place to hone our life-detecting skills.”