Summary
In this Star Talk Live podcast episode, Neil deGrasse Tyson, comedian Eugene Merman, planetary scientist Kevin Hand, and deep sea oceanographer Julie Hubert discuss the search for life on water worlds. Kevin and Julie study life at the bottom of the ocean, where they find single-cell life that eats rocks to get energy. They believe that some of the ways that life works at the bottom of Earth's oceans are applicable to how life might be surviving outside of Earth. The group also discusses the extreme environments where life can exist, such as the bottom of the ocean, dry deserts, and icy places. They also talk about the lost city, which is a type of hydrothermal vent that is a kilometer below the surface and is powered by a chemical reaction called serpentinization. They believe that a place like the lost city might have been where life began on Earth.
The discussion then shifts to the search for alien life in the solar system, specifically in the deep biosphere beneath the ocean floor. The deep biosphere is a new framework for thinking about the food chain, which is driven by chemosynthesis rather than photosynthesis. The chemosynthetic food chain could potentially work on other worlds, such as Mars, where life may exist beneath the surface. The search for life beyond Earth is focused on ocean worlds of the outer solar system, such as Europa, Enceladus, and Titan, which have vast global liquid water oceans beneath their icy shells. These worlds have good ingredients for life as we know it, and the search for life on these worlds is motivated by the possibility of discovering life forms similar to those found in the deep biosphere.
The group then talks about the technology needed to explore Europa, a moon of Jupiter, and the potential for discovering life there. The Europa Clipper mission, approved by NASA, will orbit Jupiter and make flybys of Europa to map it out in detail. The goal is to potentially answer the question of whether or not there is life beyond Earth. One of the biggest challenges is the radiation environment, which can cause software malfunctions in the robots used for exploration. The technology exists to melt through the ice and explore Europa's ocean, and the partnership between Woods Hole Oceanographic and JPL is working on designing robotic vehicles that are small, robust, and easily deployable. The ultimate goal is to get samples from Europa's surface to detect evidence of life without bringing samples back to Earth.
The discussion ends with a reflection on the history of science and the potential for all scientific fields to come together as one. Overall, the discussion is optimistic and emphasizes the practical and life-affirming aspects of the search for extraterrestrial life. The guests also discuss the importance of protecting other planets from contamination and the need to study life in its natural environment rather than bringing it back to Earth. They also talk about the potential for a new age of ocean exploration and the importance of valuing and preserving our home planet.
